Acropolis

[SubzeroLT]

Sad to read about the AT & clam

Which section did the compressor leak come from? FYI, I had a leak that came from the copper pipes rubbing the edge of the sump (something to keep in mind). 

[JiaEn]

  On 4/25/2021 at 8:32 AM, SubzeroLT said:

Which section did the compressor leak come from?

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It's at the pipe joint at the compressor end.  The compressor was one of the units left by the previous owner when we bought the house. So it's been many many years. 

[Guest]

Sorry for your loss...

[JiaEn]

Thank you @Willy Guccivera Yap.

 

[JiaEn]

The Road of Recovery

The recovery process is slow and painful. A few more coral were too weakened from the temperature shock,  and bleached a long the way. Some others, spurred on by the stress,  starts to put out more growth shoots. 

Corals will have to take their time to recover. 

 

[JiaEn]

Dynamics of Bacteria

One of the most potent, but invisible, part of the reef ecosystem is that of the bacteria. Different bacteria population wax and wane as the reef conditions change. Even in the most stable of reefs in the wild,  the bacteiral composition fluctuates regularly. Similar in our reef aquaria, bacteria plays a key role in keeping the system stable. In fact,  we reefers often manipulate bacteria population to tackle various problems in our reef tank. 

Therefore it is worthwhile to understand the dynamic of bacteria growth, such that we can have the correct expectation as to how a bacteria product should work. 

 

Most Ideal Conditions 

Let's look at the simplest situation, where we start with a single bacterium, and let the population grow. Suppose there is plenty of resources and no competition, how would the bacteria population change? 

Bacteria reproduce through binary fission.  This is the process wherrby one bacterium splits into two. So the single bacterium becomes two,  two bacteria becomes four,  then 8, 16, 32..... This results in two very interesting implications.

1. At the early stage, the number of bacteria increases very slowly,  it will take a few cycles of fission before there is a meaningful number of bacteria in the system. 

2. At the later stage,  the bacteria growth is impressive. One trillion bacteria can become two trillion in the same duration as it takes for one bacteria to become two. 

 

For Our Reefs

If we keep this in mind, some of the things we do will make perfect sense. 

When we cycle the tank, the bacteria need the time to divide and colonize all surface. Because of the dynamic of how bacteria grow, very often the nitrification capability (which depends on the number of bacteria) stays low for many days. Does adding more bacteria from a bottle help? Not really. The existing bacteria in the aquarium,  which have been dividing for a few days, is much more than what little bacteria there is in any bottle. 

For those who carbon dose, it is often recommended to start with a smaller amount. The bacteria dynamic explain this very well. At the beginning of carbon dosing,  the number of bacteria (the species we want) is low. As a result,  they can only make use of a small amount of carbon. The unused portion may end up taking up be nuisance species, causing problems in the aquarium. Therefore, it is prudent to matching the carbon dosing to the bacteria growth dynamic.  Which means start with a small amount,  and slowly increases as the bacteria grow. 

 

This is a very crude picture of how bacteria work. I will discuss a more realistic model in the next post. 

[JiaEn]

Bacterial Dynamics (II) 

In our reef aquarium,  bacteria will not grow indefinitely. The limitations of space,  nutrients, oxygen, and chemical warfare plays an important role to decide the size of the bacterial populations. Since we manage bacteria to ensure there is sufficient nutrient export in the aquarium,  I would like to propose a simple concept: target bacteria population. this is the population of bacteria needed to metabolise the nutrients to be exported. An aquarium with higher bioload needs a larger population of bacteria to export the nutrients. While a aquarium of smaller bioload cannot support a large population of bacteria in a stable way. 

 

Phases of Bacteria Growth

Perhaps you have seen a curve like this before. The sketch below illustrates the growth of bacteria in a system. 

The vertical axis represent the bacteria count, while horizontal axis represents the time. When bacteria is first introduced in a system,  it needs time to adapt to the environment. This is the lag phase, represented by the magenta portion. The bacteria hardly grows - and since they don't grow,  they will not take up nitrates and phsophates in a meaningful way. After the bacteria is adapted,  they enters the exponential phase,  represented by the blue portion. The growth at this stage is similar to the ideal condition described in the previous post: the impact of bacterial growth is small at first,  but grows rapidly towards the last moments of this phase. As the nutrients started to be used up,  the growth slows and eventually we arrive at the stationary phase, represented by green. Here the bacteria reproduces and dies/removed at the same rate, and the bacteria count is largely constant. Finally,  if the nutrients run out,  or if the enviroment becomes adverse,  the death phase takes place, represented by maroon.  The bacteria population drops,  and may stablise at a lower level. 

 

For Our Reefs 

We want to achieve two things in our reefs:

1. Keep the bacteria population at the stationary phase. 

2. Match the stationary phase population to the target bacteria population of our reef. 

The first point is simple. When our reef environment don't fluctuate too much, the bacteria population will generally fall within the stationary phase after tank cycling. 

The second point, on the other hand, is a lot more important. When the bacteria population match the export need, everything will be breezy. If the nutrient as a whole increases in a balanced way,  the bacteria population will increase,  and level off at a higher stationary phase. The problem comes in when some nutrients are not available,  or some conditions may be adverse (such as antibiotics,  or lack of oxygen). Then the population of bacteria can no longer increase. The exporting will be insufficient. 

 

/unrelated full tank shot/

[JiaEn]

Test the Un-testable 

One core challenge of reefing is to simultaneously provide (inorganic) nutrient poor water, while provide ample nutrition for reef animals. 

Nutrition poor water,  that's easier to test and manage. With competent range of test kits available,  we can have a good grasp of the (inorganic) nutrient level in the aquarium. Should the level deviate from our preference, there are many ways to correct the problem. 

Nutrition, however, is a much greater mystery. Other than when we add food into the aquarium,  we know precious little about amount of available food in the system. How long does the added food last in the aquarium? Does the animals only get to feed for 30 minute a day? If we can answer these questions,  then we can confidently keep nitrate and phosphate at near zero levels,  while ensure different type of corals can thrive. 

Turns out,  we can test it. 

 

The Organic Test

The test kit in question is not made by any commercial vendors,  but nature itself. 

Sea fans. 

Sea fans are non-photosynthetic,  and rely on capturing planktonic preys from the water column. In the presence of suitable food,  the polyps extends rapidly.  When the food becomes scarce, the polyps retracts. The contrast is obvious,  and the response is rapid. 

In my aquarium, zeostones are agitated every hour to dislodge mulms for export and feeding. When that happens,  within a minute or two,  these sea fans will have their polyps fully extended. They remain this way for about 45 minutes,  before the polyps started to retract. Until the zeostone gets churned again,  and the cycle repeats itself. 

So I would infer that in my aquarium,  corals have useful amount of nutrients 45/60 of the time. This also tell me that corals can get significant amount of energy need from feeding. Then I will have the confidence to drive nutrient even lower. 

Spider sponge showed some growth. Hopefully it confirms the good level of food in my reef. 

 

Use filter feeders as test for nutrition. What do you think? 

 

[JiaEn]

I'm slightly obsessed with sea fans recently. 

Their polyps can be really pretty and colorful. 

 

On a separate note,  the sps did grow quite a bit. Although I don't keep kh at elevated level, the growth is still satisfactory.  Looking at the aquarium everyday, I don't feel much of it. However,  comparison to past photos is very telling. 

May 2021 vs Sept 2020

[L0rdDracula]

Nice growth! Following

[SSunthar]

  On 1/8/2021 at 4:07 PM, JiaEn said:

After lurking the forum for a few years, allow me to share my reefing experience. This is my aquarium-in-progress.

ACROPOLIS

Acro:           1. (greek) the highest point; 2. Acropora, a genus of coral

-polis:          (greek) city

This aquarium draws inspiration from the famous Acropolis of Athens. This scape reminds me of the majestic ruins on top of the acropolis, the meandering path climbing upwards, as well as the sprawling civic districts at its feet. Coincidentally, the name also can be interpreted as acropora city, a good fit of the corals home to this aquarium.

I did not document the build and the transitions, but I would like to share my experience here. 

I'll start with the overall visions i have for this set up.

• My aquarium should be balanced-minimal. There must be large open space balanced by dense growth and complex structure. There must be large organisms balanced by fine details.  Although minimalist is the characteristic of this aqua-scape, the balance is the soul. 
• The feeding tube on the right side and the labyrinth on the left encourage fishes to adopt a more natural behavior. They will take advantage of the shelter in the main scape, only to venture out into open when opportunity (feeding) arises. This creates a interesting shifts in dynamic.
• The rock work is the skeletal foundation of the main "acropolis", but I want organic growth to obscure most of it. eventually the rock should be almost invisible.
• The tank is placed in the corner of the living room. Therefore it offers two-sided view. The aqua-scape needs to be well proportioned for both view; there should also be minimum clutter of equipment on the viewing side.
• Uniformity is over-rated. I want to direct flow at where flow is needed; shine light on where light is needed, give food to where the food is needed. Efficiency is the name of the game here.
• My reefing decision needs to be deliberate. if a hardware is setup in a certain way, I must be able to justify how it helps my tank to do better.

This aquarium is still work-in-progress. 

Thank you for reading, and feedbacks. 

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Wow.. a beautiful tank with an interesting aquascape.

[JiaEn]

Sea Fan Plus

Sometimes,  what we want and what the nature designed to be, are at odds. When I start to keep the sea fans, I intended for them to be a few unobstructive growth on the corner of the sand bed,  kind of like a fringe growth. 

Alas it's not to be. 

Sea fans are non-photosynthetic. Therefore they require good low to filter feed from the water column. As such. They have the structure to catch the flow,  just like a paddle or sail. This is fantastic, except that the tiny rock they are glued on cannot stay in place.  The sea fan always topples,  bends and generally require daily adjustment. 

Solution?  One huge rock to glue all the sea fan together,  while making sure they don't touch each other. 

Now they can wave all they want,  and there is no risk of toppling any more. 

This is the big red sea fan with tiny white polyps. New resident. 

 

A two side view of the Acropolis. 

[Ody]

Nice tank bro!

Sent from Singapore Reef Club mobile app

[Mzzmml]

Beautiful reef journey


Sent from Singapore Reef Club mobile app

[JiaEn]

Alkalinity : More Than Meets the Eye

Ask any reefer worth his salt,  he will tell you keeping a stable alkalinity in the reef aquarium is of paramount importance. Most reefers soon learn to test,  and suppliement alkalinity reasonably well.  

However, how does alkalinity influence the activities in the reef?  Many reefers will say it helps to build the coral skeleton. This is true,  but there are much more important processes requiring alkalinity in the aquarium. 

 

What is Alkalinity 

Alkalinity is a system of buffers. A buffer helps a mixture to maintain its pH within a reasonable range. It's like a shield,  so to speak.  When an acid is added into the seawater,  alkalinity (the shield)  will wear down first,  before pH starts to drop rapidly. Conversely,  when an alkaline is added,  alkalinity will increase first,  until the capacity is exceeded. Then the pH will skyrocket rapidly. 

So first thing to remember, alkalinity protects against both downward and upward shift in pH. This is one of the most crucial function of alkalinity in reef. 

We can test the alkalinity by the process of titration. We add acid to the water sample until the alkalinity is depleted, and the pH dropped sharply. That's the buffering capacity of the water. 

 

Source of Alkalinity in the Reef

The alkalinity in the reef comes from two different buffer systems: bicarbonate /carbonate buffer and borate buffer. We shall look at these briefly so that we can have a good picture of what's in our sea water. 

Firstly,  let's talk about borate buffer. Element Boron exists in seawater,  but in small quantities (5ppm or so). Therefore the capacity of the borate buffer in a reef aquarium can be as high as 20% of the total buffer capacity. Boron is used by reef animals,  but the consumption is rather low. Therefore it's not critical to test boron (no harm though). What we should keep in mind is,  the titration reports total alkalinity.  This means that the titration tests (salifert,  alkatronic,  etc) does not report the carbonate hardness (dispite many product says so).

Then,  the bicarbonate buffer. Bicarbonate ions are much more abundant (about 150 ppm)  in seawater. As such,  they are doing most of thr heavy-lifting for the buffer in the sea. The interaction of bicarbonate with the rest of the reef is complex and interesting. I'll spend the next post to discuss it. 

[JiaEn]

Carbonate Hardness

Let's carry on from the previous post - alkalinity is not carbonate hardness,  just that in most reef aquarium,  most of the alkalinity is contributed by bicarbonate buffer. Bicarbonate buffer system is extremely important,  not just for the corals, but for everything living on the Earth. So,  what is a bicarbonate buffer?  Without going into too much details, bicarbonate buffer consist of three chemicals: dissolves carbon dioxide, bicarbonate ions and carbonate ions. These three chemicals exists in seawater at different concentrations,  and their ratio will determine the pH of the sea water. 

When the carbon dioxide level in the sea water increases - perhaps due to respiration of animals; or perhaps due to excess carbon dioxide in the atmosphere due to human activities. The carbon dioxide reacts with water,  and eventually releases hydrogen ion,  which can cause the pH to drop. Thanks to the buffer system,  carbonate ion will take up this hydrogen ion (and turn into a bicarbonate ion), prevent the pH from dropping rapidly. 

This buffer system also allows the ocean to soak up large amount of carbon dioxide from the atmosphere. Without it,  the effect of global warming will be even more pronounced. 

All these happens without the need of any intervention of living things. The bicarbonate buffer system defend the lives on the Earth,  every single moment. However,  it is not invincible. Remember seawater has a buffer capacity?  The bicarbonate buffer cannot absorb carbon dioxide from air indefinitely. As the amount of dissolved CO2 increases,  the pH of the ocean drops, abeit slowly. This is called ocean acidification.  As we will discuss later,  even a relatively small change in pH can affect living things dramatically. Thus CO2 emission really impacts coral reefs in many different ways. 

* the mechanism of bicarbonate buffer is simplified in this post. 

** the bicarbonate buffer is also responsible for maintaining our blood pH,  as well as regulate our breathing. 

[KnightMatthew]

  On 7/3/2021 at 9:48 AM, JiaEn said:

Carbonate Hardness
Let's carry on from the previous post - alkalinity is not carbonate hardness,  just that in most reef aquarium,  most of the alkalinity is contributed by bicarbonate buffer. Bicarbonate buffer system is extremely important,  not just for the corals, but for everything living on the Earth. So,  what is a bicarbonate buffer?  Without going into too much details, bicarbonate buffer consist of three chemicals: dissolves carbon dioxide, bicarbonate ions and carbonate ions. These three chemicals exists in seawater at different concentrations,  and their ratio will determine the pH of the sea water. 
When the carbon dioxide level in the sea water increases - perhaps due to respiration of animals; or perhaps due to excess carbon dioxide in the atmosphere due to human activities. The carbon dioxide reacts with water,  and eventually releases hydrogen ion,  which can cause the pH to drop. Thanks to the buffer system,  carbonate ion will take up this hydrogen ion (and turn into a bicarbonate ion), prevent the pH from dropping rapidly. 
This buffer system also allows the ocean to soak up large amount of carbon dioxide from the atmosphere. Without it,  the effect of global warming will be even more pronounced. 
All these happens without the need of any intervention of living things. The bicarbonate buffer system defend the lives on the Earth,  every single moment. However,  it is not invincible. Remember seawater has a buffer capacity?  The bicarbonate buffer cannot absorb carbon dioxide from air indefinitely. As the amount of dissolved CO2 increases,  the pH of the ocean drops, abeit slowly. This is called ocean acidification.  As we will discuss later,  even a relatively small change in pH can affect living things dramatically. Thus CO2 emission really impacts coral reefs in many different ways. 
* the mechanism of bicarbonate buffer is simplified in this post. 
** the bicarbonate buffer is also responsible for maintaining our blood pH,  as well as regulate our breathing. 

Sibeh chim

Sent from my SM-N986B using Tapatalk

[JiaEn]

  On 7/3/2021 at 9:51 AM, KnightMatthew said:

  On 7/3/2021 at 9:48 AM, JiaEn said:

breathing. 

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Sibeh chim

Expand  

Oops 

Next one will be better... I think... 

[JiaEn]

Carbonate and Reef Animals

After looking at the abiotic (not related to biology) function of bicarbonate buffer,  let's look at how reef organisms,  such as corals and algae, make use of this important ion. 

 

Redfield Ratio

although Redfield Ratio is often mis-apllied in the reefing context (take a look here), the various life form on the reef inevitably needs some elements,  Carbon, Nitrogen,  Phosphorus, Iron,  etc. When we talk about carbon,  aquarists will often think of organic carbon dosing. However the carbon atom in the bicarbonate ion is an important contributor of the carbon element into the biomass.  The process of fixing this carbon into biomass takes place through a familiar process: photosynthesis. 

 

Photosynthesis

In terrestrial plants. The process of photosynthesis consumes carbon dioxide, and produces glucose and oxygen. Same process happens in aquatic environments. In addition,  may photosyntheic organisms can take up bicarbonate ions instead of dissolved carbon dioxide, and consume them during the photosynthesis process. 

 

Reef Building 

Of course,  one most observable function of bicarbonate ions is the formation of coral skeleton. The coral tissies concentrates ions such as Bicarbonate, Calcium,  Magnesium and Strontium,  and cause them to precipitate and forms their skeletons. Thus the coral grows bigger. 

 

Nitrification

The process of nitrification consumes bicarbonate ion. Fortunately, during denitrification,  the consumed bicarbonate ion is "refunded".  Therefore if the nitrogen cycle is allowed to proceed to completion,  then there is no net consumption of bicarbonate.  On the other hand, if nitrate accumulates in the aquaria,  or is removed through other methods such as water change or algae refugium,  then there is an overall decrease in bicarbonate during the whole process. 

 

I'm sure you will agree with me: bicarbonate is responsible for many crucial biological activities in the reef aquarium,  far beyond building the coral skeletons. Therefore, ensuring that there is a stable and appropriate supply of bicarbonate in the reef aquarium is of paramount importance. 

We will explore this further in the next post. 

 

[JiaEn]

Measuring KH

Since kH plays so many critical roles in the reef tank,  it's no wonder that most reefers keeps a close watch at the kH level of their aquarium.

For the longest time, kh are monitored across a relatively long period of time - we monitor the kH level of the reef aquarium every (few)  day, and confirm that the level of supplement is in line with the consumption.  Hobbyist titration kits are easy to use,  and reasonably accurate for our needs. 

In recent year,  however,  automatic testing of kH becomes much more mainstream.  With the likes of alkatronic,  kH keeper,  kH director, etc.,  modern reefers have many options to take a closer look at the kH of their aquarium.  It's within the reach of hobbyist reefers to keep track of the kH every hour,  and automate dosing process to keep the kH within very close tolerance. 

It's not a hard requirement for reefing.  Many aquariums are run well without any KH monitoring. However,  I do appreciate such timely data, especially when adding corals and clams to the aquarium. When coral or clams are added, they need time to adapt to the environment, before encrusting and growing. A close monitoring of kH level allows us to know when to increase the supplement to cater to the needs of these new animals. 

That's why I had been considering a kH monitoring device for my aquarium. 

 

Automatic Titrator

Vast majority of kH monitor works similarly to our basic kH test kits. A dosing pump delivers a volume of aquarium water into the test vessel.  Then,  a standard acid is added slowly to the test vessel, while the pH is monitored using a probe. The volume of standard acid used to drop pH lower than the set point allows us to determine the kH of the solution. 

The process is straight forward,  and the accuracy is high. However,  the cost of achieving this accuracy is the large amount of aquarium water needed to conduct a test.  If we were to conduct a test every hour,  and each test use 50ml of aquarium water. We are looking at 1.2L of water used every day.  This is a big hurdle for me,  especially because I do not do regular water change. 

Another challenge presented by these type of devices is that the pH probe,  and the dosing pumps needs to be well calibrated. Any bubbles in the dosing lines could affect the measurements. 

 

That's why I held on for a long time before committing to a device. At the end,  it wasn't a automatic titrator. 

[JiaEn]

Kh Measurements - Alternative 

I end up getting a kH monitor.  The device

does not use reagents, 

does not produce waste liquid,

does not require frequent calibrations. 

Too good to be true?  In most cases,  it would be.  But thanks to good science and clever engineering,  there is a solid alternative for kH monitoring. 

 

kH measurements (Part II) 

Other than titration method, there is another way for us to determine the carbonate hardness of the aquarium. For a carbonate buffer, such as seawater, the kH,  CO2 concentration  and pH are correlated. This means, if we know the pH of the aquarium,  as well as the concentration of CO2 in the water,  we can reliably calculate the kH of the water. You can take a glance at this article.

Such measurements is not without its challenges. Firstly, in order for the kH calculations to be accutate,  the pH measurements must be very accurate and precise.  This requires properly calibrated pH probes which is accurate to 0.01 pH. Probes which can do this with consistency are generally very expensive. Not to mention frequent calibration is needed. 

Secondly,  measuring of carbon dioxide concentration in water is expensive and inaccurate. Therefore if we want to measure the kH in this way, we have to solve two expensive problems: accurate measurement of absolute pH and CO2 concentration. 

 

Engineering to the Rescue 

Fortunately. There are ways to bypass these costly problems. If we can't measure the CO2 concentration in the water,  can we adjust the sample to a known value?  Turns out we can.  By bubbling the sample water, we can make the CO2 level in the water to be the same as the air around it. Measuring CO2 concentration of air is easy and cheap. 

This, however, means we still need to have an extremely accurate pH probe, as well as a (cheap)  meter to measure CO2 level. Again,  engineering to the rescue. 

 

An Elegant Solution 

If we have two samples of water,  at the same temperature,  same CO2 concentration. Then the difference in kH is only affected by the difference of the pH of the liquids. 

And if we bubble two liquids with the same air. They will have the same CO2 concentration. If we use the same pH probe to measure the pH of both solutions,  then the difference in pH can be measured very accuratly. 

[ for example,  two liquids at pH of 8.01 and 8.03 respectively.  The difference in pH is 0.02. If a pH probe is not well calibrated, it may read 7.99 and 8.01. The difference is still the same] 

This neat trick completely bypass the need to accurately measure any CO2 level, or having to measure the absolute pH. 

Oh wait. There is more icing on the cake. Since nothing (except air)  is added into the sample,  the water can be return unchanged to the aquarium. In addition, since it's not based on titration,  the sample volume does not matter at all,  which means there is no need to calibrate the sample pumps at all. 

All in all,  in my opinion,  too good but true. 

 

AquaWiz 

The device is AquaWiz.

I have been using it for more than 2 month. It runs very well for me. I'll write more about it in the next post. 

[L0rdDracula]

nice post! followed your advise and waiting for your next post

[JiaEn]

AquaWiz

So how exactly does this AquaWiz work? 

Well,  the device starts by filling the two sample tubes with water. One of them form the aquarium, while the other from the internal reservoir. 

When the samples are in place, The airstone starts to aerate both samples, for a long time. At the end of the aeration, both samples will achieve equilibrium with the environment, and have the same CO2 concentration. The sample preparation is complete. 

The pH probe takes the measurement of one sample, and temporarily stored in the device. Then,  the dosing pump empties the tube, and transfer the other sample into it. The pH of the second sample is measured with the same probe. 

Since the two samples have the same temperature and CO2 concentration, we (or the device) can calculate the kH of the tank water based on the known kH of water in the reservoir. 

When is done. The water from the aquarium is returned,  and the device updates the kH reading to a web server. 

This may sound complicated.  However, in actual use,  the device just do all these on its own,  with little input from the user. 

 

Accuracy

As with all test methods,  the accuracy of the test depends heavily on calibration. In this case,  the measured kH value of water in the reservoir. 

When we measure the kH values for calibration using, say,  salifert test kits, the accuracy is limited (0.3 dkh per step).  Therefore,  even if the device measures down to 0.05 dkH,  I would not pay much attention to the last digit.  If a more accurate kH kit is used for calibration, then the afforded accuracy will be more meaningful. 

Having said that, AquaWiz produce consistent results, which agrees with my random sample tests with salifert. More than enough  for hobbyist use. 

 

Pros

After 2 month of hands on with AquaWiz, allow me to share some pros and cons of this device. 

The advantage of thr AquaWiz is very obvious. There is no reagent required, and no wastage of aquarium water. In a long run, this will translate to substantial cost savings,  especially if the test is done hourly. 

Secondly,  the nature of measurements place little demand on the accuracy of the dosing pumps,  as well as the pH probe. This translate to less calibrations, and potential cheaper replacement of parts. 

Third, the device has a kH-pH output,  it can easily be integrated into modern aquarium controllers, such as the apex system. The device also comes with an additional dosing pump,  used for compensation dosing based on measurements. 

 

Cons

Nothing is perfect though,  and the device has a few quirks. 

Firstly, the use of air pump translates to vibratory noise. Putting it in the sump cabinet reduce the noise somewhat. However, if you are used to dead silent aquariums,  the noise is definitely quite audible. 

Secondly, the device does not have a "test now" function. In fact,  such a function is not meaningful for AquaWiz because it takes 30 mins or so to complete the test - much longer than doing a simple salifert test. In a way, the device is designed for regualr monitoring, rather than on-demand testing. 

Thirdly, AquaWiz does not have an on-board storage of past data. All results are kept for only an hour in the device. The data is uploaded to the web server and stored permanently. It's also able to output the kH value to any pH monitor. The lack of onboard storage maybe a deal breaker for some,  especially if the wifi coverage in the sump is poor. 

 

That's it. My take on AquaWiz. I'll be using the data I obtain from it for the next few posts. 

[JiaEn]

Tank thread needs colourful photos... Here is one.  

[JiaEn]

When (Not)  to Buy an Alk Monitor

Alkaninity monitor and controllers has been a step forward in reef keeping. Not only do we keep tabs on alkalinity on a continued basis,  it also allows us to do so with much improved accuracy and precision (then again,  we don't need 0.01dkh accuracy anyways). For an alkalinity controller, such as the Aquawiz,  or Alkatronics,  it can carry out compensation dosing to keep the alkalinity level of the aquarium within a narrow range,  resulting in a very stable environment. 

Therefore without a doubt, alkalinity controllers can be a valuable assets in reefing keeping.  The question some reefers may ask is,  should I get one?  In my opinion,  this depends on where the reefer is,  in terms of his reefing journey. Allow me to share my views. 

 

Alkalinity Management 

Among all the water parameters a reefer having to manage. Alkalinity is one of the easiest to master. Short of some massive accidents, alkalinity consumption is relatively stable;  at the same time,  alkalinity supplement is straight forward, and the result of supplement is generally immediately visible. 

Therefore I feel that knowing how to manage alkalinity, and success in keeping alkalinity stable through correct level of supplement is both achievable and important for a reefer. Without the understanding to manage alkalinity well, it will be an uphill battle to manage nitrate, phosphate and a plethora of parameters critical for reefing success. 

For reefers who have yet to "learn the trade" I advocate learning to manage alkalinity by themselves first, after they succeed, then can start to consider automation. 

 

It's Good to Have One

If we are not looking for complete transfer of responsibility in alkalinity management, and instead want to be more involved in finessing the dosing regime, an alkalinity monitor is a formidable asset. 

Firstly it confirms a few critical information for me.  If the monitor shows stable level of kH,  then I have good confidence that both the dosing, and my corals,  are doing well. If my dosing pump messed up,  it will reflect as kH fluctuations.  If my coral is unhappy and not calcifying,  it will also show up as kH fluctuations.  What if both are messed up and the effects cancels out?  Well. Since both issues are something unlikely to happen, having them happen at the same time is even more unlikely.  Thus I am fairly confident to accept alkalinity stability as indicator for these aspect of my aquarium. 

Secondly, it provide me with an hourly rate of the alkalinity consumption in the aquarium. Which part during the light cycle does the system consume most alkalinity?  Is the system limited nutritionally?  If I feed the corals 30mins before peak calcification, will the calcification rate goes even higher? Data gives us insights, precise and specific data gives us more insights. From here, then we can draw meaningful conclusions and make sound choices. 

 

This is why I bought an alkalinity monitor.