FRESH WATER FISH

1. Decide how much water you will replace and prepare that much replacement water in a clean container. Add dechlorinator according to the package instructions. You can buy dechlorinator at any pet store. Testing kits for other water in the tank, if at all possible. Used correctly, the aquarium siphon will not harm them. However, if you must remove the fish, fill a clean bowl/container with some water from the tank you are going to clean. This keeps the fish in familiar water and reduces shock. Then, gently remove the fish from the dirty tank with an aquarium net, and put them in the new container with the water.
2. If you have a buildup of moss on tank walls, then use an aquarium sponge or clean, soap-free cloth to loosen it now. Some people leave this alone, as it is preferable to green water and provides food for many fish. Removing plankton from green water requires an old or expensive filter.
3. Maintain your filter in staggered fashion to your water. When you change your filter, don't change your water. When you change your water, don't change your filter.
4. If you will change your filter now, too, keep at least some of the media inside the filter intact: it contains beneficial bacteria that help break down the ammonia that the fish produce. For example, if your filter has a sponge in it and a charcoal pack, replace the charcoal and keep the sponge.
5. Use an aquarium vacuum/siphon to suck out a maximum of 50% of the tank water. If possible, though, keep up with water changes and change only 10% to 20% of the water per week. This rate can climb as high as one third per day in persistent, threatening turbidity. Push the end of the vacuum down into the gravel and move it around. Aim for any visible debris. Generally, the vacuum will take up the debris and the gravel will fall back to the bottom.
6. Rinse decorative items (plants, rocks, etc.) that were in the tank with clean, room temperature water if they appear to need it.
7. Scrub the tank with new sponge, towel, or other type of cleaning cloth (be sure that whatever you use

Tips

• The most important part of cleaning the tank is keeping the water temperature constant. Fish die, usually, from the shock of going from warm to cold water.
• Put the fish into small plastic air tight bags half filled with old tank water when taking them out to clean the tank. When you've cleaned it, float the bags with the fish in them in the tank for 15-20 minutes. This will ensure that the water temperature is the same in both the bag and the tank.
• Frequent, small water changes are better for your fish than infrequent, large ones, since abrupt changes in water chemistry or temperature can shock fish.
• You can pick up a plastic tank siphon at any pet shop or even a discount store.
• Rinse everything that is going back in to the tank completely, to remove any algae, slime, etc.
• Change carbon according to the instructions (or don't even use it at all), since old carbon can leak poisons back into the tank.
• Act fast, as the fish in the bowl are running out of air. If they are breathing air from the surface constantly, put the air hose in the bowl.
• Live plants cost a bit more than their plastic counterparts, but they can help to keep the aquarium chemistry balanced and healthy.
• Avoid putting too many fish or fish that are too large in a small tank. They will crowd each other and produce waste too quickly.
• Do not overfeed your fish. 1 flake per fish, per day. It's bad for the fish and excess, uneaten food can contribute to the production of harmful ammonia.
• Consider getting your tank a cleaning crew. Shrimp are natural cleaners, eating algae, dropped food, and other debris, plus they're fun to watch. Various bottom-feeding fish perform similar roles. Snails also scavenge, but they can be a bit messy and some types can reproduce prolifically. These critters won't do your job for you, but they can help keep the tank healthy in between cleanings. Ask at a good pet or aquarium store or look them up online.