What is a good way to get rid of nitrates in a closed, circulating system? I have been doing daily 10 gal water changes on my system which has 2 40-50 gal tanks and a sump that consists of a large black bucket of unknown capacity. It has been sufficient for a while, but of late my octos have shown a decline in appetite. How might I reduce the nitrate level in the system?

for me live rock and macroalgea has done wonders. i have 0 nitrate right now! yes!

Yeah, macro algea does do wonders! A skimmer actually does help to take out the really nasty stuff to keep the trates lower for longer.

Where does one get macroalgae?

Are you close to the ocean?

Order it from marinedepotlive.com liveaquaria.com fishsupply.com There is TONS of places!

I have a ton of chaeto right now, and unlike the places listed above, I won't make you pay $30 just for shipping :)

Dan

or lots of live rock have it already on them. you just have to pick the right peices

I do live near the ocean. How would I identify such algae? And how much does it cost if I were to buy it? And are there any special things I need to have to keep the algae alive? How much should I get?

well i have a species of calerpa in mine and it looks like a bunch of bubbles on a single shaft. it grows pretty quick. i don't have anything special. just a powerhead to keep off detritus and such.

It doesn't require special lighting or anything of that sort?

I'd stay away from caulerpa, it can pollute your tank. Macros will grow fine under normal-output fluorescents, but they do grow faster with more light.

Dan

i believe that i have caulerpa racemosa. what are the dangers? how do i keep the tank safe for an octo??

When caulerpa decides to reproduce sexually, it releases thousands of spores into the water and most of it dies. If you wake up to a cloudy tank, this is probably the culprit.

There are also environmental concerns. I think C. racemosa is OK, but C. taxifolia is invasive and is currently conquering the Mediterranean. I believe California and Florida already have laws against owning it.

Dan

ok so after it releases those spores can i get rid of them?? will the octo be in danger?

The releasing of the spores is what you want to avoid, and its difficult to predict more than a few hours in advance.

This is why I use chaeto and not caulerpa.

Dan

so what do you do after the spores are released?? how do they harm the octo?

I've never had it happen to me, but I suppose once they're released you can desperately try to change the water or filter them out before they decompose, create an ammonia spike, and kill the more fragile things in the system.

If you are looking for anything reef related, check and see if there is a reef club or saltwater club in your area. Things like macros grow like mad, and people always have extra.

Is this macro algae anything I could go and harvest from the bay nearby? I am currently on the Maine coastline of the Atlantic. There are a couple of researchers and an aquarium club at our school (which I am currently at), but it's hard to get a hold of people over the summer.