Holy high nitrates Batman!!

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Fish@Work

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Jun 4, 2004
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Hello all.

I've got a serious problem here.

We have a 90 gallon marine tank here at work. In the past week, there is a red algae that has form along the top of the rocks closest to the light. There is none of this red algae on the floor of the tank. Furthermore, there appears to be air bubbles stuck to this red algae. Needless to say, this is quite a consern. I have tested the water quality and here is what I have:

Ammonia : 0 ppm
Nitrate (no2) : .25 ppm
Nitrate (no3) : 140 ppm (yikes!!)
PH : 8.2

So yeah, the nitrates are a bit high. lol

Filtration is through a single Powerhead 802 with a foam insert.

What is this red algae? How can I get rid of it?
How can I lower my nitrates? I am going to do a 10% water change tonight, and bug my boss to pick up a gravel vacuum. There is an under gravel filter, but I don't think i does jack. Please help. :)
 
is that the only circulation in the tank, the 802? i would think i would want a little more circulation in it if i were you. i would have at least 2 802 power heads in a 90 gallon tank, probably a little more if it was me. i had an undergravel filter in my first marine tank, and yes it worked, but my nitrates were always high from stuff getting stuck in it. all the leftover food and waste gets stuck in the substrate and just causes more nitrates. i had to do water changes every week, about 15% just to keep the nitrates down below 20ppm. is there anything else like rock in the tank?
 
Well I cleaned out the filter tonight and got rid of some old food that was sitting behind the rocks. I'll have to check the levels again tomorrow.

Yes their are rocks across the back of the tank for the fish to hide behind or around.
 
Sounds like you have cyano- the dreaded red slime.

There are several things you need to do to help eliminate it:
First- get those nitrates down! Big frequent water changes are in order- 10% won't touch it. I'd do 50% a day until they are under around 10, then you can slow down a bit. 140ppm is just terrible- bad. When you are siphoning out water get as much of the cyano out as possible.

You need lots more circulation- cyano forms most readily in dead spots where no flow hits. You need to keep the water moving, and have your rockwork setup so that water can move freely. Four powerheads plus a hefty return pump is not overkill.

Are you using a skimmer? If so crank it up all the way. If not, get one asap. Those dissolved organics in your water column are most of your problem.

Cut down your feeding. Food leftovers rot rapidly, and overfeeding does no one any good.

Cut your photoperiod down to fewer hours per day.

Use reverse osmosis water for topping off and water changes. Most tapwater contains all manner of contaminates including phosphates which again- feed your algae problem. Do you have a phosphate test kit?

I'm sure there is more you can do, but these are the high points.

Increase circulation, skim heavily, do massive water changes, stop feeding so darn much, and make sure the new water you put in is as pure as possible.
 
Not in a SW environment. Nitrites have very low toxicity because of the extreme concentration of Cl- ions. if you use this calculator: http://www.practicalfishkeeping.co.uk/pfk/pages/nitrite_toxicity.php
you will see the level of NaCl required to detoxify .25ppm nitrite is FAR less than that found in a marine system. The nitrates are a definite concern though..
 
When dealing with fish yes, when dealing with invertabrates no.

0.25ppm nitrite will kill invertabrates alot faster then 140ppm nitrate will, but thats going off topic.
 
Gealcath said:
When dealing with fish yes, when dealing with invertabrates no.

0.25ppm nitrite will kill invertabrates alot faster then 140ppm nitrate will, but thats going off topic.
Click to expand...

There is an invertabrate in the tank. A cool looking red and white shrimp.
 
OK I screwed up. The tank is definatley NOT a 90 gallon. It's more like a 45 gallon. I have decided to give the tank a thourogh cleaning, but before I begin, I need some advice.

The rocks are covered with a hairy green algae. I plan to take them all out and powerwash them. THere is another filter in the cabinet below the tank, which is a large Fluval canister filter that has not been used in months. I hope to rebuild it and use it. I don't have access to enough RO water, so I'll have to use tap water. Is it ok to treat it with Aqua-Plus only? I am also going to vacuum the gravel.

I'm just looking for general precautions/advice. To avoid a high bacteria loss, what precautions can I take during cleaning. What should I do with the fish and invertabrate while cleaning?

Thank you very much for being to patient and helpful. This tank will look wonderful when everything is said and done, and I will post some pics.
 
Don't powerwash your lr. You will lose anything that lives in there including the good bacteria. When you do your wc place the rock in the water you have removed and scrub with a new toothbrush or the like. If you are going to vacuum the sand be careful. There are all sorts of micro organisims you want to keep. I have never used any chemicals so I don't know what to say about the Aqua-plus. If I were you, I would beg, borrow, or steal ro water. Tap water is more than likely the cause of your hair algae.
I am by no means an expert and hope somebody else comes to post. I do know that the advice I gave is good. I just don't know what else I can help you with. Good luck and keep me informed. I wish I was there to help you. Sounds like quite a challange. Take pics if you can.
 
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