[Complexity]

Hi, I hope someone where can shed some light on a very stressful situation that I have.

I have a 6.6 gallon tank, it's new and has not established the bacteria cycle yet. But I tested all the tests that I know of to ensure the safety of the water for the fish.

Here are the specifications:
- I have 4 neon tetras, 1 Otocinclus sp, and 1 female guppy, along with initially 3 male guppies. I didn't want an extensive amount of babies so I only got 1 female. I understand that this might be too many fish for a 6.6 gallon but I supplemented the tank with an extra filter and air stone/air pump. To my understanding if there is no overwhelming amount of toxic materials the fish should be ok (not dying at least).
- I have a plant for the algae eater.
- All fish seem healthy especially the neon tetras I had no issues with them what so ever.
- The female guppy has also been fine with no issues for the past few days since I set up the tank.
- Water Temperature, sustained @ 25C or 77F.
- PH level, 7.2 - 7.4 sustained.
- Ammonia level, 0 or near 0.
- Nitrate, 0 or near 0.
- Nitrite, 0 or near 0.
- Oxygen supplemented by air stone/pump.

None of the fish died other than male guppies. 2 died leaving only 1 left who also doesn't look very healthy.

 

[Chesh]

Complexity! Welcome to TFK! Sounds like you found us while searching for help with a tough situation. Sorry to hear about your losses. . . but glad that you're here!

As you've noted, there are several potential issues with your setup. . . in my experience with keeping guppies and neons (both of which prefer different types of water hardness), they DO need more room than a 6g tank. I'm looking forward to keeping Ottos, they prefer to be kept in groups from what I've read.

That aside, the numbers that you've posted - while not bad - show that your little tank isn't cycled yet, as you noted already. In situations where you have a lot of fish in a small pond, so to speak, the toxin levels will typically fluctuate wildly. I'm sure you know how lethal ammonia is to fish, and I'm guessing by all those pretty 0's that you've been really keeping up on your water changes in this tank - a good thing, for sure - but my guess is that the ammonia is still spiking very quickly between water changes, which is going to put a lot of stress on all of these animals. This, combined with the fact that they're likely already stressed from recently being moved into a new environment is most likely why you're having trouble. :/

Of course the recommendation would be to get a bigger tank, more water will go a long way in helping you to get through a tricky situation with minimal loss of life. The ideal here would be to return the fish, cycle the tank without them, then bring them home - preferably not these fish in this size tank, a single Betta would be more appropriate for a 6.6 gallon environment. . . adding live plants, if possible, can *help* in keeping things a bit more stable while the tank is cycling, but there is only so much they can do. . . there is no getting around the dangers of an overstocked and cycling tank, I'm afraid. . . and even if you get them through the cycle, you're going to run into trouble with this many of these fish in a tank of this size. . . sorry to say.

All of that said, in my experience with Guppies I have found that - as hearty as livebearers can be, the 'fancier' the fish, the more sensitive. Selective breeding seems to have taken the Guppy from one of the most adaptable fish around, and turned them into a far weaker (if prettier!) animal. I've found that the females, typically being less showy and presumably less selectively bred, tend to fare better in conditions that are less than ideal. This is simply based on my experience with these fish, I could be off here!

But this is really all guesswork. . . these fish are still so new that it is entirely possible that they were ill to begin with. . . which doesn't change any of the above, but. . . *shrugs*

I hope that this helps out somehow. . . sorry you're having such a difficult time.