URGENT HELP NEEDED
 

My fish are ill.

I started with 5 neons. They've been fine for three weeks.

Added 6 guppies, 2 days ago, only 2 left of those. I came home tonight and the neons are Very pale sitting on the bottom of the tank, the two guppies are swimming irratically.

I've got no idea whats wrong with them. Tested the water yesterday, 0 ammonia, 0.1 nitrite and about 40 nitrate. Performed 25% water change yesterday to dilute the nitrate.

Please, has anyone got any idea of what might be wrong? It must be something to do with the new guppies?

is the tank cycled?

How big is your tank?

Edit: Also, I wouldn't worry about the Nitrates. I was a bit worried about them as well as mine were hitting 80 and my LFS did the test on their heavy planted tank with angelfish and it only took 2 minutes to hit the 160 marker on the API test. Angelfish are much less tolerant than guppies and neons ;)

I'm guessing from your nitrite reading that perhaps you've added too many fish too soon.

I would also suggest that you carry out a series of water changes and keep a close eye on the water parameters, and keep feeding to a minimum.

Thanks for the replies guys. I really appreciate it.

I went to bed last night completely gutted and expected to find a tank full of dead fish but was quite pleasantly suprised this morning. The neons are back to their old self, swimming around in a shoal brilliant red and blue again (such a relief!) but I'm down to one guppy now. The remaining guppy seems happy enough, no signs of stress yet. I'm lost as to where the other guppy is! He's obviously passed away but I can't find the body! Its bizzare.

I performed a 25% water change the day before yesterday, is it worth doing another?

I'm not buying any more fish for a while, I'll let these guys carry on as they are.

Well, for now they seem a lot better than last night and I just pray that they'll be ok. Do the symptoms I described suggest any common ailments?

Again, any help is appreciated :)

Yes.:)
It seems nitrite poisoning is the top cause of your problems and ammonia from the start. Kate had explained clearly that water changes will help get rid of nitrites. In the end, you want zero ammonia and nitrites and nitrates not exceeding 40 ppm for your fish to thrive.

I've carried out a 25 - 30% water change.

The fish seem better than last night but 1 particular neon is staying on its own for some reason, quite inactive. He's not sitting straight in the water, slightly wonky. He's not on his side, just leaning slightly to one side.

I'm worried that no matter how often I carry out water changes, these poor fish are on the rocky road to death.

Are their any additives I can add to the water to help them? Its so frustrating !