MAJOR nitrate problem, what should I do?

[alphanguy]

Here's my info:

Established tank, 10 years old... undergravel filter, 10 gallon
Had various fish over the years, until they died slowly, and was left with one neon tetra. 3 months ago, I got 5 male guppies, and 2 females from a friend... MAJOR live births, poulation went to 42 fish, (2/3 of them fry)I've reduced the fish population in the last 3 weeks to now only 18 fish. They are hoveing near the surface and acting stressed, Ammonia 0, Nitrite 0, Nitrate 200 ppm. Obviously, the Nitrate is through the roof. I hadn't vacuumed my gravel in over 2 years (when I just had the one neon), and even when I got the new guppies, I didn't, but 2 weeks ago I finally vacuumed the gravel, thinking with the large amount of fish, it would need it... but it's about 5 days after the first vacuum that the fish started to stress. I've done a 20% water change 7 days ago, 3 days ago, and a 30% water change yesterday. What else should I do? The testing shows my alkalinity very low as well, not sure why.

 

[CaptainAhab]

If you are going to keep the UGF you need to clean under it. Cap one of the uptubes, get some PVC to create an "L" (one str8 piece and an elbow). Hook up a shopvac to it and let it go, then cap that side and do the other (assuming you have 2 sides).

You might consider a 80% change as well, or a series (8-10) at 20% a day

 

[meegosh]

If it were me I would ditch the UGF. I would bet that is part of your problem. UGF's have become pretty much obsolete with all the advancements in filtration. I would get a hang on back style filter, like an AquaClear 20. If you wish to keep the UGF, follow CaptainAhab's advice.

I would also see if you can get the population down some more. 18 fish, even if they are small guppies, is way too many in a 10g. I would try to give some away or if you have larger fish, use them as feeders.

I'd do some large water changes immediately until you get the nitrates down to around 40ppm. That is the highest I would let it stay at. I would shoot for below 20ppm if possible.

 

[alphanguy]

I just did a 60 % change, nitrate after change reads 30 ppm... I'm felling a little better about it. Should I add some salt? I CAN clean from under the filter.... would it work if I take the gravel out (not rinsing it) and take EVERYTHING out, and clean up the filter... then put everything (including fish) back in (but not rinsing any of the gravel or decor)?

 

[alphanguy]

meegosh... I had BOTH a penguin bio-wheel and UGF for quite a few years, and fish kept dying on me all the time, as soon as I ditched the bio-wheel, everything stablilized and I had no deaths for 4 years. So, who knows? things thsat work for other people seem to not work for me. The bio-wheel also sprinkled water on my wall behind the tank and ruined the sheetrock, not exactly friendly to one's home.

 

[bs6749]

It's a 10g tank so my suggestion is to put the fish into a container, dump all of the water, and rinse out the gravel/sand in warm water. Then put everything back into the tank including all fresh water. That's going to be your easiest way to reduce your nitrates immediately. I also recommend that you ditch the undergravel filter. You don't really need a filter as long as you keep on top of the water changes and gravel vacuuming.

 

[alphanguy]

update

Wer'e getting ready to have a TON of snow tonight, and my nitrate was reading a bit higher, about 40ppm... so I did ANOTHER 50% water change, it now reads 10ppm... the guppies seemed to act better for a few hours, now they are hovering at the top of the tank again.... nitrate is STILL 10 ppm, so I guess that wasn't what was making them hover at the top of the tank?

 

[bs6749]

Wer'e getting ready to have a TON of snow tonight, and my nitrate was reading a bit higher, about 40ppm... so I did ANOTHER 50% water change, it now reads 10ppm... the guppies seemed to act better for a few hours, now they are hovering at the top of the tank again.... nitrate is STILL 10 ppm, so I guess that wasn't what was making them hover at the top of the tank?

That's not possible. If you have a concentration of 40ppm and remove half of the water and replace it with pure water, your concentration will effectively be halved. You should be seeing nitrates of approximately 20ppm. It is possible that you see over 20ppm if you had 40ppm to start with and removed half of the water. This means that your water has nitrates in it.

 

[alphanguy]

Well

I've had a few more deaths, their tails turned black over the course of a few hours, and then kicked the bucket. I'm down to 13 fish now. Some in there are acting fit as a fiddle, it's strange. I suppose a 10 gallon tank won't hold more than 2 guppies or something without them all dying, it's hardly worth it.

 

[bs6749]

I bet if you tested your ammonia right now you'd see quite a bit of it in there. It should have been 100% water change or nothing IMO. When you added fresh water you most likely converted the ammonium ion into ammonia and killed your fish as a result.

 

[alphanguy]

Isn't that what I did?

In the last 24 hours, I've done 3 PWC's... one 30%, and two 50%. Isn't that basically a 100 percent change? I just did another ammonia test, and it read .30, a little higher than before, but not in the danger zone. It's so strange that my problem started almost exactly a week after I vacuumed the gravel for the first time in 2 years, I probably should have left it alone.

 

[fearlessfisch]

Google "old tank syndrome" and you might get some tips about handling this. I think you are right that massive changes in water conditions after so long have been a tremendous shock to your fish, even though you technically made the conditions "better."

I am so sorry.

 

[bs6749]

In the last 24 hours, I've done 3 PWC's... one 30%, and two 50%. Isn't that basically a 100 percent change? I just did another ammonia test, and it read .30, a little higher than before, but not in the danger zone. It's so strange that my problem started almost exactly a week after I vacuumed the gravel for the first time in 2 years, I probably should have left it alone.

You said that your nitrates were over 200ppm. Removing 30% of the water means 70% of the ammonia will still be in the tank. 200 x .7 = 140ppm. Then doing a 50% change cuts the level to 70ppm. Another 50% change cuts it to 35ppm. You said you had 40ppm and this is exactly where your tank is since I based my numbers on 200ppm to start with and you had over that. This is just proof to you that this is how it actually works. Like I said, it should have been 100% changing of the water or nothing. You can't do anything about it now except to change out more water. I'd change 90% of it bringing your nitrate reading down to below 5ppm. So instead of changing 10g all at once you have changed about 25+ gallons after doing the many PWC's. See why I said change it all at once? By the way, I'd consider .30 to be pretty high and you should do something immediately.

Google "old tank syndrome" and you might get some tips about handling this. I think you are right that massive changes in water conditions after so long have been a tremendous shock to your fish, even though you technically made the conditions "better."

I am so sorry.

The conditions aren't necessarily "better". Granted there was "clean" water put into the tank, but that clean water most likely converted unharmful ammonium ion back into the toxic ammonia form and this is what is killing the fish.