Desperate for Help on Nitrates

[KarenH]

I previously made a post on how I added some chaeto, and immediately after, I got a huge Nitrate spike. One month later, that Nitrate spike is still there. I'm really getting concerned that this is starting to affect my Soft Corals as it's been a month now.

I have a 72-gallon bow front tank.. (everything Is posted log), and do weekly 3 gallon water changes. This hasn't affected the nitrates.. Yesterday I did a 9-gallon water change and re-tested today using two different tests, and Nitrates haven't budged off 80 ppm.

I haven't changed my my feeding habit of my fish, I use half a cube of Mysis shrimp and half a cube of Emerald Entree in the mornings. This tank is almost a year old and this is the first time I've had this problem. I've tested my saltwater mixes, my RO water, and everything else I can think of.

I do have a refugium with Mangroves and Chaeto growing in back with constant lighting. If anyone can give me expert advice on how to get this stuff lowered for good, i'd be so appreciative. Should I do a bigger water change? If I do will that make my tank completely cycle all over again? Help!!

[weez1959]

You shouldn't have ammonia or nitrites in there.
What's in your filter? Also what kind of substrate are you using?
I find that a weekly 3 gallon WC is not much. When I had a 75 I was doing 12 gallons every 2 weeks. If you have Crushed coral your trouble could be coming from there also.
Are there bio balls or fleece in your filter that hasn't been changed?

[KarenH]

My Refugium has Mangrove and Chaeto growing in it. I currently have live sand that's been there since I set up the tank, but the bio balls I never even considered.. yes I do have those and haven't cleaned them I'll give that a try.

[weez1959]

Take them out completely and instead add a bit more cured live rock instead.
The bioballs are probably your problem. Just taking them out will make difference. you could maybe run some new carbon and a polyfleece for a few days too but don't forget them there...

[charlie]

Weez probably has this pegged!! I wouldn't take them all out at once tho, probably 1/2 at a time, so as to not totally shock your system. Remeber, slow is better!!

[weez1959]

oops, forgot that one!

[charlie]

No problem, you are the only one here that pegged the bioballs.

[weez1959]

I've read so much negative feedback on those silly little balls! I've never had them in my system but figured it had to be those causing the problem.... but why does she have ammonia and nitrite readings?

[charlie]

I didn't see a mention about ammonia is this thread. She had ammonia on 8-14, and I do think that reading may be attributed to some die off in the chaeto when she added it, same with the nitrites. I am only guessing here!

Karen, could you do us a favor and post your most recent test readings, aside from the nitrates!! If you do have ammonia and Nitrite readings, there is something else going on here that we are not seeing.

[weez1959]

I was looking in her log and saw it there. Might be gone by now since there are no dates.

[charlie]

I hope it is gone, that is why I asked for all her tests. I am thinking that if she didn't mention them, they are not present at this time. I hope she posts back on this thread!!!

[KarenH]

Yes I'll post them now.. As of last night, my Ammonia is at zero, it's only the Nitrates that won't go down.

[KarenH]

Thank you so much for your advice, I would have never though of the bio balls. Last night I removed half of the balls and replaced them with new ones. I've also added de*nitrate in my pump, and plan on doing an 8 gallon water change tonight. I'll keep you posted... Thank you both again, you're awesome !

[charlie]

Karen, take the bioballs out of the system entirely, do not replace them.

[KarenH]

OK.. will do!

[Rod Buehler]

If you havent gheard already why bio-balls produce nitrates...

Bio-balls colonize with areobic bacteria (High oxygen due to the oxygenrich water passing over them). Aerobic bacteria is superior at convertingthe amm>nitrite>nitrate, but thats where it stops. Without LARGE water changes, the nitrates tend to accumulate.

Within our live rock and deep fine sand beds Anaerobic bacteria colonize. Anerobic bacteria also does a good job at amm>nitrite>nitrate, but then goes one step further by passing off the nitrates into the air as a harmless nitrogen gas.

If you are trying to harbor both types oif bacteria (aerobic, and anaerobic) in the same system that are competing for the same 'food source' neither will live up to their full potential.

Also the ammont of water change that you are doing will have little effect in lowering nitrates. Its a numbers game.. My math isnt the best and I may have too many zeros, but I think you will get the idea.. if your nitrates are at 100 PPM thats like .00001. if you remove 10% you are only removing .000001 nitrates which still leaves .. well, a whole lot of nitrates . and by the time you do your next 10% they will have climbed back up to the starting point of 100...

After you getthe bio-balls removed you will need to do a series of large water changes (30-50% or more) to succesfully lower the nitrates. If nitrates are somewhat low to beging with, the rock, deep sand and macroalgaes can keep up with nitrates, but if they are way high, nothing can keep up except large water changes.

Good luck

[charlie]

Thanx Rod, good way to explain that!!!

[weez1959]

What he said!
You were doing 3 gallons out of 72 which doesn't make much of a water change at all, I think it's about a 4% water change. It could never make a difference unless you were to do it twice a day and even then, you're not diluting the problem much

[Poseidon]

Great explanation Rod, that details exactly why I have never been a fan of small weekly water changes.

[KarenH]

Thank you all for your valuable help and info, I would have never thought of the bio balls. And if my small weekly water changes aren't helping, what would be a good schedule? Maybe Semi-weekly of 12 gallons like Weez suggested?