Algae in captive reefs

[blueheaven]

Hi guys, I have been thinking about this controversial issue recently and I find it worthy of a serious discussion.

Firstly, I'll state the rules:

1) No flaming or insulting comments

2) Only constructive comments are allowed

3) Spam comments will be requested to be deleted

4) There's no right or wrong, just share your views

5) No deviation from main topic (eg. What type of macroalgae for refugiums?)

Ok, now that I've set things straight, let's have a healthy discussion on this topic.

Here are my views:

Algae exists in almost every place, it is only natural to have it in our reefs. I remember Daniel asking Anthony Calfo about cyano in natural reefs and his reply was that if cyano didn't exist, we probably won't too!

Actually algaes in captive reefs serve much more a purpose than spoil the image of the reef itself. Algae that grows on rocks and walls serve as a food source for herbivourous fish and inverts. Not simply as a food source, but also a food source which contains much more energy than other types of food.

Energy from the lights are being converted into biomass and stored energy in these plants. The herbivourous fish, being a secondary consumer, would receive the most amount of energy by directly consuming the algae. It bears the same theory why going vegetarian would give you more energy than meaty foods.

The energy from the algae is then converted to biomass in the fish and the waste products from fishes serve as another energy source for other organisms. As a rough guide, about 60% of the total energy taken in by the fish is being given off in its waste. This makes fish waste "energy packets" in which organisms, especially the saprophytes will then take in this energy and the cycle goes on.

Most importantly, most corals do contain zooxathellae which is also a form of algae (for those who still do not know). The byproducts of photosynthesis by these algae in the coral's tissue would provide the coral with nutrition. By considering that certain corals will be able to give away its zooxathellae and then capture new ones, it seems to me that zooxathellae is essentially important to the coral.

In conclusion, I am an advocate of having algae in our reef systems. Although there is a threshold to the nutrient levels in our tanks, we should not shun away from algal growth as it is all part of the natural ecosystem. The only problem which most reefers have misunderstood or have a misconception is that if I have that small patch of greens on the rock, my water parameters must be out of hand. This might not always be the case as I still have small patches of algae even though I have undetectable levels of nutrients. The problem will only arise when we have minor (yes, minor) cases of eutrophication where there is excessive algal growth due to an excess of nutrients.

[blueheaven]

Any inputs?

You do not have to write legthy comments like mine

Just tell us what you think about the issue

[CKS]

Agree with your points!

my only concern is that they'll grow over other stuff im trying to keep and inhabitat their growth..

ive 1/3 of my sandbed covered with hairalgae, but my pods populations seems to be thriving as well (after ive removed the fishes)

Of coz i do find them astatically unpleasant, so i am trying to boost the growth of my macroalgae by supplementing with iron hoping that they'll outgrow the micro

so to conclude, i do not see it as a tank crash, end of lifespan, time to restart..etc

its just a natural process that has to happen for good reasons.. and i'll take time to get it under control..

of coz i can just throw in lots of trochus snails + long spined urchin.. but that'll spell the end of my macroalgae too

[nakazoru]

Could not agree more.

Think about it is that we all tries to get the balance right but found it near impossible to acheive it.

Like algae, ich is part of the ocean for another reason. One strive and the other will perish. ich strive and fish perish. algae strive and coraline perish.

Anyone who are able to mimic a ocean like tank at home that is most similar.... That will be my dream comes true. Impossible but god himself... The creator of the ocean...

[giantbicycle]

Just maintain it,and watch out for growth till its like

[pangz]

i dun have hair algae, but brown algae (cyano?) does grow on the glass. Have to clean it on a daily basis otherwise the glass not clear. I did spot a tuff of hair algae a long time ago, but think my yellow tang ate it up because it suddenly disappeared.

I read that phosphate contributes to algae growth and currently there is about 1/2 Lt of rowaphos in my 3ft by 2ft by 2.5ft tank in a filter bag, not running any FR. Tank is about 1.5 years old.

[blueheaven]

Yes, what Edwan posted is a fine example of eutrophication in our tanks

Unless your tank is like that, it is not much of a concern other than aesthetics

As for algae which you scrape off the glass, I've read that these contributes a certain extent to phytoplankton in the system.

Does anyone have opposing views? We'll like to hear them

[hamannbmw]

This might not always be the case as I still have small patches of algae even though I have undetectable levels of nutrients. The problem will only arise when we have minor (yes, minor) cases of eutrophication where there is excessive algal growth due to an excess of nutrients.

how do u know u have undectectable nutrients Any test kit to support yr case ? BTW what is nutrients ?

[RAV-65]

Nothing opposing or objectional here...

But although like you said, there are algae in the ocean and it's unavoidable as its a part of the ecosystem...

But there are also pockets of reefs in the world whereby the corals thrive in a low algae infestation environment, where delicate corals like SPS grow in relatively low nutrient and low algae waters.... this is wat I'm trying to replicate my reef to be...

After all, we all try to replicate the ocean dun we?

[blueheaven]

how do u know u have undectectable nutrients Any test kit to support yr case ? BTW what is nutrients ?

Ok, I have undetectable ANN and phosphate all tested using salifert testkits

Vincent, thanks for your views but I thought corals need a certain level of nutrients to grow. As long as we do not go beyond that threshold, it would be ok.

And neither should we go under the threshold

[hamannbmw]

Ok, I have undetectable ANN and phosphate all tested using salifert testkits

Vincent, thanks for your views but I thought corals need a certain level of nutrients to grow. As long as we do not go beyond that threshold, it would be ok.

And neither should we go under the threshold

what about insoluble PO4

[patrick123]

I think algae are effective and economical way to reduce nutrient....particularly PO4 and Nitrate. However, growing them in the display tank can be very unsightly....similar to the picture posted by Bro Giantbicycle. So it is best to have a refugium or a place to grow the macroalgae outside of the display tank.

Regards,

Patrick

[blueheaven]

But what about microalgae that grows on rocks and walls?

And bro hamann, I'm quite satisfied with my undetectable phosphate levels using titration testkits. I feel it's good to have some PO4 in your water too

[blueheaven]

Good to hear people having success with vegetable filters

I also have good results with macroalgae

I would also love to hear with those who are growing caulerpa and those with algae in their systems, be it in a refugium or un the main tank

[weileong]

You can have so-called low (abit undetectable) nutrients in your water but hotspot for nutrients built up on the LR and sandbed. Low nutrients don't refers to getting undetectable PO4 and NO3 from your testkit, there is more than that.

Does it feel better if you have people agreeing that some algae in the tank is normal?

Cyano does exist but in what proportion? One big patch here and there? or they are present but not in big porportion that can be seen easily?

Blueheaven, same goes for the big patches of green algae on your LR. Like I said, if you think that is fine then it's fine for you but IMHO, that's too much algae. Or you want to wait till a tank turn into marine planted tank then says it is excessive algae?

[blueheaven]

Well those algae have stopped growing already

Now I am looking for stuff that will help me clear them

Luckily it's not those hair algae or bryopsis

And I would also love to hear from people who think that we should not let algae set foot in our tank. It's a discussion right? No taking of sides here

In Anthony Calfo's book, he mentioned that small patches of cyano is considered a norm but he also put it in a comical way such that we should not have so much that it can eat reefs and the family dog too!!

[weileong]

If you don't have your own opinion then how are you going to have a discussion?

You seems to imply that letting algae grow in your tank up to the extend of what you currently in your tank is fine? Or am I reading it wrongly? pls clarify.

Yes he said small patches but how small? Maybe small patches end become a big patch lol.

[andysho]

Hi weileong....

long time long time never been to be able to see your tank

in real life

Hope one day can come your house and see your tank again lol

Anyway thumbs up for your well mantained tank lol

[hamannbmw]

And I would also love to hear from people who think that we should not let algae set foot in our tank. It's a discussion right? No taking of sides here

lol... who want algae in their tank... hands up

[andysho]

Well i think no one will put up their hands ,

but for some fishes~~~ those algae are their favourite lol

[weileong]

Let us get the intention of the reefer who started this thread right.

From what I read, he is asking for opinion on how much algae we can have in our tank. Certainly all reef tanks will have some algae in it, this is natural and cannot be avoided. However the point is how much algae is considered normal?

The imporant thing is to keep all the algae under control, if you can see the algae from far away then it is considered out of control already.

[patrick123]

Blueheaven bro, I read somewhere that if you can keep your PO4 below 0.03ppm, all the micro/nuisance algae will die off. So if you see some micro algae, chances is that you have PO4 in your water.

The goal in this hobby is to keep the PO4 as undetectable as possible. The point is that if you think you already done your best, and you are satisfied with it. That's good enough.

If you keep up with your rowaphos replacement, and control your feeding, I don't see why you cannot achieve "no algae" tank.

Regards,

Patrick

[iantoh]

hi everyone, just thought id add my two cents in. bear with me ya.

i think low nutrients is certainly the thing to strive for in captive marine aquariums, because with constant feedings, we are already supplying generally more than adequate nutrients into the micro-ecosystem. even when test kits reveal undetectable levels of NO3 or PO4, like bro weileong mentioned, it does not mean these nutrients arent present, but just that these nutrients are being utilised as soon, or as quickly, as they are being formed. if you notice, green algaes, diatoms, and cyano always grow in areas near the sandbed, or on certain rocks but not others. thats likely due to the release of such nutrients from the sandbed and from certain rocks with higher trapped nutrient levels.

from what i understand, in order for one to encourgage macroalgae growth insofar as to outcompete microalgae growth, one has to have NO3 and PO4 within the Redfield Ratio, which basically say that for every one PO4 molecule utilised by algaes in cell growth, sixteen NO3 molecules are also used. so for one to use macros to succesfully outcompete micros, one would have to have a proportion of NO3 and PO4 in this exact ratio:

according to this theory, microalgaes will proliferate if your parameters for NO3 and PO4 fall outside the white central boundary, because even with super low phosphates, as long as food is fed, and nitrogenous by-products are produced, then microalgaes will grow, because micros require far less PO4 than would macros due to their size, and furthermore, micros are able to directly utilise NO4 before it gets the chance to convert to NO3 whilst macros can only uptake NO4 when NO3 is first present.

as i think its hard to really always keep NO3 and PO4 in these ratios, maybe the next best way is to try to minimize nutrients as best as one can.

well, thats all for now.

cheers everyone!

ian

[Bob]

Great Info Ian

[CKS]

Thanks iamtoh!!

very useful chart.

but i cannot minimize nutrients as best as i can because im trying to do marine planted tank..guess it'll be a balancing act