Hi there. I have been doing some research also on making a filter. I have read through the posts here trying to work out what I need. I will be using an old pool cartridge filter (pump and cartridge removed). I think it's perfect as its already water tight and hoses will attach easy. As for the pump, I have a submersible bilge pump (meant for pumping water out of a boat). It's rated at 1100 GPH. I'm not sure if that pump is ok as i doubt it is designed to run constantly and I'm also thinking that it will be too strong. I don't know how many gallons my tank is as I don't have it yet but it will be 6 foot long.
Do I need any valves gauges etc? Should the water be filtered from top to bottom or the other way around?
Any help would be appreciated