High Ammonia Levels!!

[fish 4 life]

Hey guys i have a 20 gallon tank that has been setup for about 2 months now. I had high ammonia levels in the beginning (which killed my F8 puffer) but then i started to use reverse osmosis water which lowered it back to 0. I thought my ammonia problems were gone so i bought two pangasius catfish. A week after i got them the water started to turn cloudy i tested the water the levels were 0 nitrite, 0 nitrate, 7.3 ph, 1.00 ppm ammonia!!!!! It ended up taking the lives of my two pangasius!!! What the heck is going on????? I did a 25% water change today and plan on doing another tomorrow..
PLEASE HELP!
This is my filter at the bottom it has 1 inch sponge, 1/2 inch filter floss, 1 inch carbon bag, biomedia

This is a shot of my tank

[Suckermouth]

If I had to guess, your tank is cycling. This is common in newly set-up tanks where the bacteria that naturally consume ammonia have not yet established. These bacteria will naturally colonize a tank with fish in it as fish produce ammonia. In established tanks, the bacteria are in high enough populations to manage the ammonia output, but these bacteria are not yet present in high numbers in a new tank. After your F8 puffer died, you had no fish in the tank, right? If that's the case, any bacteria that had developed would've consumed the remaining ammonia, and then dwindled away after exhausting this resource. After adding the iridescent sharks, the ammonia output then likely exceeded what the small bacteria colony could handle.

Articles on cycling, the Nitrogen cycle, and New Tank Syndrome are pretty easy to find. I'd recommend reading up on it. One thing you can do is find yourself one of those bacterial additives and add that if you buy new fish; these will help jump-start your bacteria colony in your tank. Another alternative is to perform a fishless cycle; articles exist online for this as well, but basically you add ammonia to the tank artificially without fish in the tank, allowing for the bacteria colony to establish.

[kupper]

what you are experiencing is new tank syndrome .... your tank has not cycled

I would also recommend checking your PH again , RO water has 0KH and 0GH which usually causes nasty PH swings.... at low PHs your tanks stops cycling completely but in PH's under 7 the ammonia is actually ammonium

I would recommend getting your PH at 6.8 stable and feed small amount with some fish to get the cycle started ( hardy fish )

test your water regularly during this time and once the tank starts to show nitrite and subsequently nitrate readings your tank should be ready

[fish 4 life]

Okay when my F8 died i added 3 fish to help with cycling. The water got better so i took them out and added the pangasius.. Does my filter look to be working okay??? I will go add some cheap fish to it again but is their a better filter that would help with the growth of bacteria ???

thanks!

[Viktor Jarikov]

Sounds like a good plan. Either go fishless cycling - add medicinal ammonia solution or just some fish food which will rot and produce ammonia (something I've always done) or if you can use feeder fish for that.

I had high ammonia levels in the beginning (which killed my F8 puffer) but then i started to use reverse osmosis water which lowered it back to 0.

I am uneasy with this statement. If I read it at the face value, I'd answer that RO water changes are largely irrelevant to your ammonia levels or at least are as relevant as any other water changes (as long as the new water has zero ammonia; your tap water doesn't, I understand from that other thread, I linked below). The only thing that could bring it back to zero is the work and the sufficient quantity of the needed bacterial colonies. Or, you'd have to set up a continuous flow-through system (no biofilter, no return/recycling of water) - the ultimate water change, so to speak.

Looks like you have an Aquaclear filter, 20, or 50? They should be sufficient for light stocking levels. I'd remove carbon and replace it with more biomedia. I never use carbon. It has its place in certain situations and in certain bad waters, but 99.9% of the time, I think it is needless... sales hype.

@Kupper: some of the issues you raise have been touched upon here (same OP): http://www.planetcatfish.com/forum/view ... =9&t=36206

[fish 4 life]

Okay is it okay to leave the carbon in? How long should i expect the cycling to take? I just bought 5 neon tetras today.... And so RO water is okay to use right?

[nvcichlids]

i forsee some dead neon tetras shortly. Neons are not a great fish to try to cycle with.

[Viktor Jarikov]

Okay is it okay to leave the carbon in?
***the only harm in it that I can see atm is that it takes up the space of something far more useful for your purposes. Right now it is an inert filler.

How long should i expect the cycling to take?
*** when one starts from scratch and does not seed but does everything else right, from 3 to 5 weeks.

I just bought 5 neon tetras today....
***Aren't these tiny fish? They won't produce much ammonia, less than one 1" goldfish.

And so RO water is okay to use right?
***this question belongs better in that other thread of yours I linked. My last thought was that it was ok with keeping an eye on pH at least.

[Suckermouth]

Your filter appears to be working fine, but the problem is certainly not mechanical filtration, it is biological filtration.

Bacteria that develop from cycling is not all or nothing. The appropriate amount of bacteria develop to handle the amount of ammonia. I don't know what three fish you had in before the Pangasius but if they were significantly smaller, than the difference in bioload may still have allowed for ammonia to spike. It's less likely, though. Usually adding two fish shouldn't be a problem. On the other hand, if one of the Pangasius died (you mentioned it seemed stressed in the other thread), the ammonia could've gone up from its decomposing body and caused the other to die.

The best way to see how long the cycle will take is to measure it directly with ammonia and nitrite tests. Once both of these reach 0 again, your tank is cycled. Since your tank probably has some bacteria in it now, it may not take quite as long as the 3-5 weeks Viktor mentioned you'd expect if starting from scratch.

It's okay to leave carbon in; it's not hurting anything.

As mentioned, neon tetras are pretty touchy so aren't good for cycling. I do not recommend cycling with fish, anyway. Adding some product like Cycle may help by adding bacteria, which is preferable to exposing fish to high levels of ammonia while they weather the cycle waiting for the bacteria to develop over time.

[Barbie]

It can take 4-6 weeks to cycle an aquarium. Buy some Bio spira or Safe start and do not add more fish until your ammonia and nitrite levels are 0 and the nitrates are registering. If you lose the fish you currently have, feed the tank like there are still fish in it. I would also have to suggest a LOT more research before you add more fish. Your tank is quite small for the fish you are attempting to keep in it. This is a pictorial view of how the nitrogen cycle works. A little patience will get you a long way at this point in your fish keeping hobby ;).



Barbie