Need help with filter for 20 gal. tank

[dieselplower]

Sounds like you got the right filter. On a goldfish forum that I frequent, the moderators are very knowledgeable about care of goldfish in aquariums. They recommend that the filter gph be 10x the size of the tank. So a 20 gallon tank should have a 200 gph filter. This allows enough surface area in the filter for nitrosomonas and nitrobacter to develop to handle a proper fish load as well as a flow rate that will not cause too much current. By the way, that forum recommends 15 to 20 gallons per full grown goldfish in an aquarium. Water changes every week or two to keep nitrate under 40.

 

[Nepen]

TM, once you assembled, at the top, you will be able to shift the intake tube. The normal position is on the left, I think, if the current is too strong, shift it to the right and the current will be a bit slower. I packed more bio media in there and added more activated carbon too. I also added crushed oyster shells at the bottom of the container.

 

[bettasngoldfish]

The Marineland filters don't have as much room for bio media as the Aquaclears (and the filter cartridges can be expensive to change especially if you have multiple tanks) but I can honestly say that some of the marineland HOB that I have are still running after several years (some are at least 8-10 years old) The Aquaclear that I had was good while it lasted but I don't think I had it even two years before it quit on me. Maybe it was just a bad unit, I dunno.....