Post those articles about reefkeeping

[blueheaven]

Ok, this is a follow up from nicholas's thread. I feel that here is a more appropriate place to post articles so that beginners can read them

Here's my article on Sandbeds

Many people have conflicting ideas on setting up a refugium, especially one with a sandbed. I have seen set ups with a DSB (Deep Sand Bed) of about 4" to 6" thick. And sadly, a lot of people think that just by putting in some sand and macroalgae, they have a working refugium. I firmly say NO.

In my opinion, its important to know and understand the thing you are doing before doing it. Although sandbed dynamics are still being researched, I will provide the current information available.

Bacteria and zones

The main purpose of adding a sandbed is to allow bacteria to colonise on its surface. Many people think of diseases when the word "bacteria" is mentioned. The bacteria we are talking about here are those that convert certain compounds to another form.

There are mainly 2 groups of bacteria, namely the aerobic and anaerobic. Aerobic refers to the presence of air and anaerobic refers to the absence of air.

And the confusion comes as each group will split into 2 groups. The 2 groups are the autotrophs and heterotrophs. Autotroph meaning the organism is able to synthesize its own food from inorganic substances and heterotroph meaning

an organism that cannot synthesize its own food and dependent on organic substances.

Basically, there are 3 groups of bacteria we are interested in. The aerobic autotrophs, aerobic heterotrophs and anaerobic heterotrophs. The aerobic heterotrophs will break down organic substances into inorganic compounds (eg. ammonia). These inorganic compounds are then taken up by aerobic autotrophs which will perform nitrification. The anaerobic heterotrophs will perform denitrification.

The aerobic autotrophs are usually found on the suface layer of sand since they need oxygen and light to synthesize food. The other area around the top 1/3 of the sandbed will be colonised by aerobic heterotrophs. And as oxygen levels decrease down the sandbed, anaerobic heterotrophs will colonize there.

An important point to note is that anaerobic zone actually consisted of 2 different zones. The zone that has oxygen concentrations of 0.5-2 ppm (test conducted by Sam Gamble) is named as the "anoxic" by Bob Goemans. This zone will contain facultative (bacteria that live with or without bacteria) bacteria that fully oxidize nitrate back to nitrogen gas.

The other zone that has no oxygen at all will consist of anaerobic heterotrophs with only convert nitrate into ammonium which is a better fertilizer than nitrates for algae.

This explains why I think that really deep sandbeds are not good as your ultimate goal is to achieve an anoxic zone. The recommended sandbed depth should be 3"-3.5"

Grain size and size of refugium

Normally, people try to use the smallest grain size for their sandbed. This differs between systems and I shall explain.

It is good to have small grain size as it increases the surface area for bacteria to colonise. But this only applies to systems which have the skimmer output there or any other source of oxygenated water. If the area is in lowly oxygenated water, the oxygen diffusion will be limited to the upper layers.

For those people who have lowly oxygenated water in their sandbeds, it is advised to use bigger grain sizes and a bigger sandbed. This will allow oxygen to diffuse deeper faster.

Infauna and their importance

The word "infauna" is new to many people. It actually means the fauna (animals) IN the sandbed. So why do these animals make such an importance in sandbeds? The infauna consist of mini-stars, micro-stars, worms, flatworms and a myraid of other small animals. These infauna will constantly shift the sand and their action will prevent the sandbed from reaching a completely anaerobic zone. This action also ensures that the sand does not clump together as a result of precipitation and bacterial actions.

I really hope that LFS will start to bring in recharge kits consisting of these infauna that reefers can add to their sandbed. If not, these animals will come as hitchhikers on live rock.

Quorum Gene Sensing

This is a relatively new concept to sandbed dynamics and it involves bacteria. Quorum sensing is actually a way bacteria produce this gene that senses the population of the bacteria. The researched bacteria is the Vibiro spp. and it is found that the bacteria will produce toxins that kill human cells in high populations.

It will be interesting to do research on the nitrifying bacteria and see whether they will be detrimental in high population sizes. And we could see whether we can stop the production of the Quorum gene .

This comes to the end of my article and I hope readers will find this useful and I will type another article on different types of sumps next.

The top information on different types of bacteria and zones are from Sand Mail, FAMA Aug 2004 by Bob Goemans

[nicholasloh]

really informative good job.

i'm still thinking of wad to write abt.

[nicholasloh]

~Budget Reefing~

Ever realised that u so love that fish in the aquarium, but is too poor to provide it with an environment? well, master nick gives u some tips on getting the cheapest deals in town! First, look for a 2nd hand tank. if its within ur budget, of say $20 bucks, then get it. not only that, try to ask if the seller has LRs and stuff from his own set and buy them. this shld be around 1/2 of the cost price, and is overally affordable. with this, u will most probably get an FL light, tank, sump/cannister filter, and a pump. this are the fundementals on building ur reef. then, sit down and start planning ur tank's rockscape.try to get deals from fellow reefers, that usually sell at abt $5 per kg. this is much cheaper then outside, and they are cured(though cycling is safer!). then when u got ur LRs, start arranging ur tank's rock scape, and let it cycle for 3 weeks. now, check ur pocket, and allocate ur money to corals and fishes, or juz fishes. taking that ur light is FL, go for simple mushie, yumas, leathers, xenias and star polpys. each piece costs like $3.33 cents at Iwarna. cheap sale there.pick quantity and quality over size. it can grow if u feed it with shrimp meat(mushies and yumas only). dose my phyto plankton to ensure that the corals dun die off after a few weeks. then, after ur tank is up and running with all corals stocked, move on to fishes. these things are better bought from reefers, due to the fact that they already know how to eat and are usually ich-resistant. they are also cheaper now, see how much u haf got, and go to liveaquaria to haf a browse thru the fishes. this will let u see most of the fish in the trade. start making a list of fishes, bearing in mind the amount of bioload ur tank can take. list these fishes according to how u want to introduce them into the tank. this is very important! now that u're done. draw a back-up list of fish substitutes if ur fishes are too EX. now, u're ready to shop thru the net ! start looking out for these cheap deals. visit shops often too, and try to haggle if u can. if the fish is healthy in the LFS and feeding, take it home. anyway, in abt 3 mths time, ur search shld be over if ur tank is small. and there u haf ur amazing tank!~