Help getting filter drain to stop leaking?

Hello. I am having a real with the drain spout on my above ground sand filter. I cannot get it to stop leaking. I tried Teflon plumbing tape and 2 different caps, but they were no help. Right now I have a bucket catching the water and I pour it back into the pool every few hours, but I was hoping someone can give me some ideas on a fix. Thanks for any help.

Welcome to the forum.
At least on my Hayward there is a circular piece of soft gasket material inside the cap to butt and seal against the spout edge when you tighten it down. If this is missing or damaged it will leak. Can go to an auto parts store and but a small sheet of some soft gasket material and cut a new one. Since you said you tried two different caps I doubt this is the problem but it's my best guess for now.
Al

Thanks for the advice. I am willing to try anything now. It seems when the filter is on the pressure, which is about 12, pushes the cap out a bit causing the leak.