Nitrates are up, any suggestions?

[Polecat]

75G FOWLR, Yellow Tang, Purple Tang, Damsel and 3 inch Humu. Large wet/dry filter full of bio-balls, skimmer, 4 power heads.

Fighting the dreaded cyano-bacteria. Did a Nitrate test and voila, therein lies the culprit. Any suggestions on how to reduce the nitrates? I did a 30% water change three days ago. Water looks great, fish are great, just tired of stirring it up every day.

[Polecat]

Tested my water source, 0 Nitrates, so that's eliminated as the problem. I would think that with the limited livestock load in this tank that nitrates wouldn't be a problem. ???

Welcome to AquariumAdvice.com

What exactly are the NO3 readings and what are you feeing daily? Any additional set up info would help.

You should also realize that 3 large(r) fish in a 75g tank is not very well advised. Even if you feel they are not cramped at this time they soon will be. Keep in mind that what goes into the fish must come out , the waste the animals produce is as much a contributor as the foods used.

I would also be wary of future aggression with the trigger and 2 tangs in a small environment.

Cheers
Steve

[Polecat]

Feeding twice a day with a custom pellet mix from the LFS, and supplementing with a bit of sushinori for the tangs.

This tank has been up and running for 5 years. The yellow tang I have had since the tank's inception, the purple for 3 years, the damsel about a year and the humu about 8 months. The wet/dry is rated for 225g. I have about 30 pounds of live rock and 1" base of crushed coral.

The humu is going to live elsewhere soon, I knew he was temporary when I got him. Once he's gone, I'd like to add some more live rock and a cleaning crew, i.e. snails and crabs.

The NO3 reading last night was 100ppm. 8O

[stresco]

Bioballs will be a definate source of Nitrates. I have them in my Wetdry and my Nitrates are always between 20-40. I am working on removing them now a couple at a time over the next few weeks. Also, pre-filters on your powerheads and pump (dont know if you have any) will also trap Nitrates as will as that Bio-Bail stuff.

The addition of the LR and "crew" will help, but as you say, "once the trigger is gone".

One of the reasons most dislike CC is it's a very efficient trap for foods and detritus which over time will accumulate and can (but not always) cause problems. 100 ppm nitrates are quite high even for a FOWLR. I would definately suggest a water change as well as having the LFS confirm the reading just to be safe. You never know with test kits, they are easily faulty or possibley out of date even if recently purchased. You could also test the source water for comparison.

I think until you are able to find the new home for the Humu, it would be prudent to feed the tank once a day, but leave the nori as is. The tangs do need the grazing foods. Even though you may not be overfeeding to any real degree, the wastes the fish are putting out is part of the problem.

How long ago did you start noticing the increase in the NO3 vs any possible changes you made in the tank?

Cheers
Steve

[Polecat]

My test kit may very well be out of date, but even if it is off, the cyano is a sign that the nitrates are high. I'll replace the test kit, as well as get an independent reading from a friend.

If the CC is a problem, what is the solution, replacing it with sand? Wouldn't that be doing more harm than good? Aren't there benefical creatures in the substrate?

If sand is the way to go, how do I go about replacing the CC with sand? AND, what type of sand do I go with? Live sand is out of the question $$ wise right now.

Thanks for your help.

If you feel the CC is the culprit, it is relatively easy to swap. You can determine if it's part of the problem by syphoning some out or taking a net and scooping some from the bottom area's. If quite black, then I would say yes. Keep in mind that even sand will accumulate detritus but to a much less degree. Sand also has much more "surface" area for bacterial colonization. My tank has only 1½-2" of sand and still allows for proper nitification.

I recently did the same thing for the same reason back in December. After 5ish years with the CC, I decided it was time to go. The nitrates in my sytem were no where as bad (10ppm) but after the swap, they have never gotten above 5ppm. My system is not what you would call "typical" and relies heavily on LR and animals to keep things in line.

There are basically two schools of thought on this one. All at once or in stages.

I chose to do it in stages over about 6 weeks. Using a small 1" flexible hose, I syphoned out the CC . I visually sectioned the tank and removed 1/3rd of the CC at a time (every 2 wks) and added a plain oolitic sugar sand. This allows for the fauna to migrate over to the new sand as well as not impacting the biological filter base the bacteria provide. It was done with little effort and diruption to my tank (which is a full reef) and there were no loses or dreaded algae blooms.

>>Here<< is an interesting article that should also help.

Cheers
Steve