I plan on setting up a 55 gallon tank for swordtails and corydoras cats. Can someone tell me the best filter for this. The kit comes with a Aqueon over the tank filter rated at 400 GPH. Do you think this would be adequate? It will only filter the tank around 7 times an hour, and I believe I heard you wanted the filter the tank at least 10 times an hour if not 15?
That filter should be fine as long as you don't overstock the tank. That model should have two bags correct? If that's the case just make sure you never change both bags at the same time, wait about two weeks to replace the old one after you put the new one in. This will keep more beneficial bacteria alive so your filter will not have to cycle as much. Make sure you also do weekly water changes of at least 10-20% and at the same time use the old tank water to rinse out the pads weekly, never use tap water as this could kill the bacteria. This will also prolong their use.
WorldF, that filter is plenty. Pay no attention to the multiples of tank volume per hour unless you use a dense planting scheme. If you have dense plantings, you want to circulate the water to prevent local peaks of different chemicals. A large enough surface for your biological filtration is a real priority unless you have so many plants that the nitrogen just can't survive in the water. I use simple air driven box filters in many of my tanks and they work just fine. I doubt that I even get 2x in those tanks but the fish don't know that. They just go on thriving and reproducing. I do fill my box filters with ceramic media to make sure the biological filtration surface is large enough. Think about filter flow this way. People who make filters often put bigger pumps in bigger filters so hobbyists get used to thinking in terms of rated flow instead of noticing how much media is in the filter. The reason the higher flow filter is thought to be better is because they hold far more media. When you first clean a filter the real flow is probably at least half as much as the flow rating, but a month later it is probably much lower. It keeps right on working and converting nitrogenous wastes even though it is beginning to be plugged up and has that reduced flow. You clean it and really don't worry about the flow rate after, you worry more about damaging the biological effect of the filter by using poor cleaning techniques. No filter, short of one that will rearrange your substrate, will ever keep fish waste from accumulating on the bottom, so flow is not a real factor there either. It is up to you to remove those wastes with a gravel vac. As long as the filter contains enough media, it will be fine.