Another Nitrate Thread

[WackyInsertions]

Sorry to make yet another, but I don't think my case fits any of the others.

I have a 20g long with 7 tiger barbs, about 6 ghost shrimp, and 4 small cory cats with a 1-2 inch sand substrate. Tank is fully cycled, I do 10-20% water changes weekly, and I have two penguin filters on it each with a bio-wheel (one is for a 50 gallon and one is for a 20; together, they cycle 270 gallons per hour). I also keep several live plants and there is a small piece of driftwood. The tank gets 9 hours of light a day from a double strip, glass top.

Now, about two weeks ago, my carbon filter went very bad over the weekend and there was a horrendous algae bloom. This led to a terrible nitrate increase. I'm now consistently at 40 ppm nitrates. I'm trying to lower it because I'd like to add a few more tiger barbs and I believe my current ones are getting accumulated stress from the high levels.

Ok, so...my question. Why are my nitrates so high? I add plant supplements, which I'm thinking could possibly be raising the levels, but I only add them once a week and the nitrates are consistently high every day. I think it's a safe assumption to conclude that they would be lower about a day before I added more supplement if that is indeed the problem. Also, one of my barbs has gotten ick and another has fin damage, so I'm switching in and out of medicating with quick cure and melafix. Could those be raising it?

In case it comes up, I don't overfeed. I feed the barbs bloodworms, and they don't let even -one- of those things slip by, and for the bottom dwellers, I alternate between a pinch of flakes and shrimp pellets.

Any help would be IMMENSELY appreciated, as I'm desperate to get these nitrates down. Sorry to make this so long

 

[Allivymar]

Curious. What did you do about the algae bloom? Dead and dyin algae can contribute to the nitrogenous wastes; that may be a part of the answer. If you used chemicals to rid the tank of algae that also could be a factor. QuickCure can affect your bacterial colonies; also something to consider (btw, why are you switching between meds? I may be misunderstanding you here, but just in case, Melafix has no effect on ich. If you use QuickCure you need to treat until 3 days after you see the last ich spot).

Only way to rid the tank of nitrates is water changes. 10-20% changes once a week won't be enough right now; my 25 was getting 20-30% changes 2-3 times a week to deal with those sort of nitrate levels (although in my case overstocking was the reason).

 

[WackyInsertions]

About the algae bloom, I changed the carbon filters, scrubbed the bejesus out of the walls while doing a water change, let the filters get what I couldn't, and then cleaned the carbon filters after I was all done.

I'm switching between meds because one has ick, so I need to kill the parasites with quick cure, and another has pretty bad fin damage (he gets picked on quite a bit ), so I'm adding the melafix to help with that.

I'll try upping the water changes and see if that doesn't help (although, I'd always heard that changing water that frequently is horrible for the biological filter )

Thanks.

 

[Allivymar]

Ok, clarify one thing for me, as I'm easily confused LOL When you say switching meds, does that mean, for example, one day you treat with Melafix and one day with QuickCure? Or that you are using both at the same time?

If your tank is cycled, you don't need to be so concerned about water changes. The bacteria really don't live in the water column; they colonise surfaces like filters, tank walls, substrate, plant leaves, etc. So removing water will not really muck up your cycle. When I had my guys in the 25g, I was doing 20-30% water changes 2-3 times a week (had to, the tank was overstocked and I needed to keep the water in good condition).

The ich meds will muck up a cycle however; they tend to kill off the nitrifying bacteria. The other thing to consider, if you are doing water changes to remove the nitrates and algae, is keeping the medication levels up so the fish are being treated properly. Its tough to find a balance; on one hand you need to keep the water parameters good so as not to stress the fish (and water changes also remove some of the ich parasites). On the other hand you need to keep the meds at the right level or they won't be effective.

I'm thinking the scrubbing of the walls and the cleanin of the carbon filters may have been the reason you are having high nitrates. Chances are all that cleaning killed off a portion of your nitrifying bacteria, and it took a little while for the rest of them to catch up.

Just for future reference, a diatomic filter would be more effective in clearing a tank of an algae bloom then carbon. Of course, one needs to determine the cause of the bloom to prevent further occurances; I'm not sure a "bad" carbon filter would be the cause. In one of my tanks I never use carbon and have no problems with algae blooms, despite it getting sunlight for an hour or 2. Carbon goes useless fairly quickly anyway. Good for removing meds (btw, make sure your carbon is removed now as you are trrating your fish) and clearing a tank of tints caused by driftwood. Other then that pretty much an unneccessary added expense IMHO.

 

[TankGirl]

If you have only high nitrAtes and no ammonia or nitrItes, then just do 10% water changes every day for 4-5 days and you should be in the clear. I would also stop adding the ferts, as that would do it, to. When your plants are utilizing the nutrients properly from the water you will notice a drastic DROP in nitrAtes, so unless you are dosing CO2 it may be that you do not need to use ferts at all. Try skipping them and see how things go. Are the tiger barbs headstanding? That is usually a good indication of your water quality. A nitrAte problem is about the easiest one to deal with in an aquarium, IMO.