Hi George,I don't have a bottom drain as such,mine is what you call a top bottom drain.
You will have to dig down to about 18" below the water line and (i'm assuming you have a liner) fit a prefeably 4" flanged tank connector to give you sufficient flow to your filter then fit a 4" elbow and some straght pipe to about 1" off the bottom of your pond and continue from the other side of the flange to your filter.
You havn't said how many gallons your pond holds or what pump you are running.On a small pond of a few hundred gallons you might get away with 2" pipe but if it's over 1500 gallons your pump will probably suck the filter dry due to insuficient flow into the filter hence 4" pipe.You will also have to increase the size of the transfer ports in the filter.
Tony.
Posted on Feb 24, 2006, 8:33 PM from IP address 81.153.171.12