Discouraged

[alisiddiqi]

I say this because I recently had the same pleco and a bunch of my fish died too. This was because the pleco would suck off their slime layer and eat their scales when no one was watching

[alisiddiqi]

What is the temperature in your tank?

[homemadepopcorn]

I'm sorry you're having some trouble with this; it only gets easier with time.

First off, we need some information.

What is your temperature, filter size, dechlorinator? What kind of feeding regime do you have and what are you feeding? While I'm not assuming that there is anything wrong with any of these things, the problem might lie in one of them.

As long as there is some surface agitation, there will be enough oxygen for your fish.

[KevinVA]

I'm curious about the temperature of your tank, as well. With that rate of evaporation (while having a cover) I would think it might be pretty warm in there. Are you at the same temp as you were, when you were cycling the tank? People typically raise their temps to 82'F.

If that's the case, I would recommend slowly bringing it back to 79'F or so. Also, what is your pH? Have you had any fluctuations? I've noticed that pH shifts can cause stress to fish, dropping their immunity to disease that their symptoms could typically fight off.

[bethyMT]

Others here have given you great advice and asked many good questions of your setup. So I won't add to that. We just need to know how you "run the joint" so to speak.

I would, however, like to tell you that keeping fish is definitely a learning experience...you will have things happen that aren't what you planned. The real challenge, and the real beauty in it (IMO) is finding out why things have happened, learning about what your fish need, and understanding all about these little ecosystems we maintain. So try not to be discouraged; this is all part of the process. This is how you learn. If you take the time to analyze the situations that come up, you'll be more confident and you'll be very knowledgeable pretty fast.

And, oh yes, we have all screwed up (not to say you did in this case, but don't be surprised if you do sometime). Some worse than others. It's just the way it is. You learn and move forward.

[Rocksor]

What size is your heater for your tank?

Radical temperature fluctuations repeatedly can cause stess and death.

[KevinVA]

I just realized my last sentence didn't make sense. lol

It should have read: "I've noticed that pH shifts can cause stress to fish, dropping their immunity to disease that their systems could typically fight off."

symptoms -> systems

Weird typo. ;P

[givemean_a]

You all are asking great questions!

1. I feed my pleco Hikari sinking wafers e/o day and on the opposite day I break up an algae wafer for her and the cory.

2. My house is hot, and dry (we don't control the temp) but the fish tank is 78 degrees F. Solid but I don't know what the wattage is for the heater, I can check when I get home.

3. I use 2 filters, one is the marineland penguin 350 and one is the whisper tetra something or other, they are both rated for 30 gallon tanks, so I assume that between the two of them I'm solid for the 20 Gallon Long

4. I use prime as my dechlorinator, my pH has been steady at 6.8/7

5. For feeding, we do a pinch of flake food 5 out of 7 days

Thanks for the suggestions, I feel better about my abilities to keep these guys alive. Thanks again everyone!

[Sandz]

I feel that its just the fact that the bioload has increased over time with the tank not really being "seasoned". Its just like a cast iron skillet, you dont get the "Flavour" until you really add the grease...

What im talking about here is algae and other bacteria on all surfaces of the tank. I would suggest in a 20 gallon to up your water changes to 2-3 times a week at 20%. This will keep the tank more stable during these turbulent times and provide a removal of ammonia.

I dont know about plants in your tank but if you have some hornwart at a lfs, even for temporary use, throw a small handful in. It eats nitrates really well and provides live plant filtration as they feed on co2 and help you process ammonia.

Have you noticed any heating fluctuations? The heater could malfunction and cause a electrical current through the tank. Even the slightest can kill the fish.

I really think it comes down to newER tank, sensitive fish. Pleco's and Corries will die easily in a small tank because they are so dang hard to keep stable.

[givemean_a]

Wow Sandz! Thanks for the perspective, what a wonderful analogy! I can change the PWC schedule.

I will go to the LFS and get some hornwart, do I need to do anything else for them? Are they a floating type plant?

The idea about the electrical current makes sense, but wouldn't all the fish die at the same time?