Newbie! NEED HELP!

[hk4491]

So I just set up a 20-gallon fish tank a few days ago, and introduced some fish into it last night. They all seemed fine last night when I first put them in the tank, but after 24 hours the water turned cloudy and one of my guppies died. I did a water change right away, cause the water was a bit smelly. Am I doing everything OK? Cause I don't want any of my other fish to die.
Also here's some general info on my tank:
1-Currently, I have the temp set to around 24 degrees celsius.
2-Population of my fish: 2 small Angelfish, 2 Guppies(used to be 3), 1 Tiger Barb, 2 Mollies, 1 Pleco. Is it overpopulated?
3-When I did the water change, a lot of food came out from under the gravel, so I fear I might have overfed them. What can I do to fix this?
4-By looking at the population of my fishtank, how much food should I put for them everyday?
Much thanks to anyone who answers.

[Cliff]

Sounds like you might be overfeeding your fish and they are in a un-cycled tank

Please read the cycle with fish thread here in our forum. The is a link to it below in my sig

[Cermet]

Your tank isn't cycled. First off, you need to do a large water change; at a minimum, 75% of the water. Do this for a few days or until the ammonia levels drop below 0.25 ppm.

This brings up the second point - you need a liquid aquarium test kit to measure the ammonia, nitrIte and nitrAte levels. Most fish stores sell these. As the tank cycles, ammonia levels will tend to drop and nitrite levels will rise (these are very toxic to fish.) After more time, these levels will drop and the aquarium filter will have a full colony of bacteria (most often in the poly fill in small filters) that will convert fish waste into nitrate. Periodic water changes will keep the nitrate levels low enough to be safe.

Welcome to one of the most interesting aspects of fish keeping - understanding biological filtration by your filters. Read the section on 'Fish based Cycling".

[mizzoutank]

++++ To understanding the cycle and bacteria in your tank.

On top of the cycling information that you need to read to save your fish.
We need to address the fish that you have.

1: is it a common pleco? if so, that will get to over a foot long.
2: Tiger Barb's aren't good in that tank
3: Angel fish aren't good in that tank

Personally, I would return all the fish as the current set up you have sadly just doesn't work.

[Lady Hobbs]

You added the fish last night but today they are dying already? That's awfully fast for fish to die from over feeding, seems to me. Did you add dechorinator to your water?

Your stock is all wrong and you are overstocked, as well. The ONLY fish you have suitable for the tank is the guppies.

[escamosa]

I agree with the others. You really have to cycle your tank properly, before you add too many fishes, or any fishes. If the pleco is a common pleco, then it will definitely have to go, as they can grow huge. The Angels aren't really the best fish for a 20g either, especially during a cycle.

In basic terms, cycling is the process of growing good bacteria in your filter media (the sponge, cotton wool, filter cartridge). The fishes waste will produce ammonia, which kicks off the cycle. Once the ammonia starts, bacteria starts to grow that eats the ammonia and turns it into nitrites. Once the nitrites start, then a bacteria starts to grow to eat the nitrites and turns it into nitrates. After the cycle is complete, your tests should read 0 ammonia, 0 nitrites, and you will be seeing nitrates when you test. Get yourself an API master test kit, so that you can test for ammonia, nitrites and nitrates. Having that kit will make it so much easier to keep track of what's going on during the cycle.

When you start doing your water changes, do not change the water so that you get a 0 reading of ammonia or nitrites, and do not clean your filter. And make sure you use dechlorinator every water change. Chlorinated water will kill off the good bacteria. You need to have ammonia and nitrites in the water to keep the cycle going, until it completes. You need to keep testing, and only do enough water changes to keep the ammonia between .25ppm and .50ppm. Eventually the ammonia will lower to 0 as the bacteria grows enough to eat it all. The nitrites will do the same thing. They will show up on your tests, they will rise, then lower as the bacteria grows.

A couple of things you can do to help your fishes through the cycle, and to speed the cycle up a little, is to add some more oxygen to the water, and raise the temperature a little if you can. The bacteria that you want to grow thrives on oxygen, and doesn't mind the water a little warmer as well. So I would raise the temp to 26C, and if you can, add an airstone to increase the oxygen. You can also drop the water level in the tank a little, if you have a HOB filter (hang over the back filter), just to make the water splash back into the tank a bit more, to increase the oxygen. It can take 4 - 6 weeks for a cycle to complete.

Hope this helps, and good luck!