over crowded tank

Question
Rachel, i asked about what i can keep with a rainbow shark a few days ago and
now i want to know what to do with my crowded little tank. it is 7 gallons and is
about a year old.i have 3 small rainbow sharks that i'm watching for my friend
who is on vacation, 5 congo tetras, 5 balck skirt tetras,1 penguin tetra, and a
glass cat fish. pleasse help and thanks for the advice on my big shark.

Answer
Well, is this a temporary tank stocking? If so, really what you need to do is maintain the tank good enough so the fish have a healthy environment. Really, as soon as the rainbow sharks are gone, the tank is not that over stocked as the other fish who are in the tank stay pretty small and do not need much room. That is the good thing about most tetras. I am going to assume your friend is returning soon to take the sharks back, if not please let me know and I will revise my advice. Ok, now all you really need to do is keep a structured maintainance schedule. One of the most important things you will need to be sure you have is a good filter. Without a good filter, it will be nearly impossible to keep such an overstocked tank clean. Make sure your filter is also clean and not clogged or it does not have any build up in it. Next, you need to do structured water changes. While normally a water change should not be a big deal and only a small change every month or so, a tank like yours will require a more advanced method. Basically, you should change  1 gallon of water per week. This is to help keep the ammonia down. Also, do not add any so called "beneficial bacteria" that comes in some declorinators. Get a basic declorintor that is just a declorinator and not all the extra stuff, this will help cut down the build up of waste in your tank. You should syphon the tank every two weeks. Now, while your tank needs alot of cleaning, try not to stress your fish too much when you clean the tank. Also, with such a small and overstocked tank, keep a close eye on each fish daily to make sure no diseases or parasites are breeding in the tank. Lastly, do not overfeed. With so many fish it is tempting to give alot of food to make sure every one gets some but this can make or break your tank set up. Feed once daily and only enough for each to get a snack. Fish do not need food as we do in meals and can survive for a while on no food, so all you need to do is give them just enough to get the nutrients. I almost forgot, you will need to change your filter cartridge every two weeks with your syphon. This is to clean the water better. I suspect after two weeks the filter cartridge looks clogged, changing it every two weeks will help the tank stay cleaner. I hope this helps. If you are not up to cleaning your tank this much you could always get another 5 or 7 gallon tank. I love to have tanks around my house. It gives me the chance to have different fish and have different tank set ups. One tank can have semi-aggressive fish, the next peaceful fish, the next aggressive fish, and maybe the next goldfish. No matter what I put in my three large tanks, I enjoy being able to create different environments and being able to have the different fish I want without risking the health or happiness of any fish. However, buying another tank does cost money, especially for the heater, so cleaning your tank on a very structured schedule will help you keep the tank as it is until your friend takes back the sharks. I hope I have given you the advice you needed. Let me know if you need anything else.