High Nitrates....PLEASE HELP !

[BryGuy1188]

I have a 35 gallon hexagonal tank and it is saltwater with aprox. 1/4 liverock and apox. 2" of fine coral sand. I used to run just a undegravel filter for years before fish started dying. I bought a protien skimmer and small filter.
I have been using the N03 zero nitrate remover and did a 1/3 wate change with no results on the test stips (still bight purple).
Should I return to the undergravel filter and just keep the skimmer ?.....please advise....thanks, B

 

[CorallineAlgae]

No no no undergravel filter. You didn't put in a biowheel filter by any chance? What filter did you get? You'll need to do a series of small water changes to remove the nitrates and maybe even have to research vodka dosing. What size is your tank and about how many pounds of live rock do you have? More info is definitely needed. How many fish do you have and how much do you feed? Sorry for all the questions but they really will help us to help you.

 

[BryGuy1188]

response....

see my previous e-mail for tank size etc....I have a aquaclear filter with sponge, charcoal and bag of pellets (rather small filter)...as far as fish, I have 2 damsels.
I eventually want simply 2 precula clowns a yellow blenny??? long body burries itself in the sand at night and possibly some shimp....simple.
1 other problem is constant over-bubbling with the protein skimmer no matter how high or low I place the collection cup...any help would be greatly appreciated......thanks, B

 

[Sniperhank]

The only ways to remove nitrates are with a fuge or via water changes. How high are your nitrates? Most of us do not rely on test strips since they can be inaccurate, so what does purple mean? When was your last water change? You should be doing a 10% change weekly to keep nitrates in check.

 

[sanderson417]

I had a similar issue. I did a lot of water changes 2/week- some really big and some small and it didn't seem to help me. Someone on this site recommended Instant Ocean Natural Nitrate Reducer. I used that along with frequent water changes and my nitrates dropped dramatically in weeks. Now it could have been the combination of the two, or maybe it took a few months for the water changes to take effect. I also cleaned my socks and filters thoroughly with each water change. I hope this helps you. This site is great, because eventually someone will recommend something that will help.

 

[Ingy]

Nitrifying bacteria are aerobic bacteria. In normal SW tanks they live on rocks and the topmost layer of sand where they have access to water and dissolved O2. With an undersand filter, you are pulling both of those 2 needs all the way thru your sand. So you get aerobic bacteria in the entire sand layer which helps breakdown amm and nitrites. When you removed your sand filter those bacteria will die and the sand becomes a anaerobic (no or low oxygen environ). that will release lots of amm into the tank which other bacteria elsewhere may have a hard time keeping up with. The problem should be short lived tho

 

[Readingexcalibur]

Interesting!

 

[BryGuy1188]

Reply

Nitrifying bacteria are aerobic bacteria. In normal SW tanks they live on rocks and the topmost layer of sand where they have access to water and dissolved O2. With an undersand filter, you are pulling both of those 2 needs all the way thru your sand. So you get aerobic bacteria in the entire sand layer which helps breakdown amm and nitrites. When you removed your sand filter those bacteria will die and the sand becomes a anaerobic (no or low oxygen environ). that will release lots of amm into the tank which other bacteria elsewhere may have a hard time keeping up with. The problem should be short lived tho

I never had a problem with fish dying with the undergravel filter....then I took it out put in the protein skimmer and then the small filter......should I try replacing the filter and just run the skimmer and undergravel...?

 

[Ingy]

When you do your next water change vacuum the sand really well. That's not normally something you do but you may have lots of dead aerobic bacteria still decaying in the sand. Suck em out. Personally i would even remove the under filter completely as I keeps a dead space of water under there. Your other bacteria should be doing fine if you're only having nitrate probs.

 

[Sniperhank]

I'd put money that removing the undergravel filter released pockets of gas that built up in the sand. This could have poisoned your fish, if not caused a spike in the tank parameters. Either way it would have been deadly to your livestock.

 

[crister13]

Exactly what I was thinking sniper.

 

[CorallineAlgae]

When you do your next water change vacuum the sand really well. That's not normally something you do but you may have lots of dead aerobic bacteria still decaying in the sand. Suck em out. Personally i would even remove the under filter completely as I keeps a dead space of water under there. Your other bacteria should be doing fine if you're only having nitrate probs.

Excellent advice. I agree 100%.

OP, your power filter and skimmer are not causing this. They are both part of the long term solution. People abandoned using undergravel filters because they are highly prone to pitfalls. Believe all of us who have had years of success with saltwater aquariums. None of us would ever use one and our tanks are much better without it. Infinitely so. With a little work your tank will be fine.