I have a problem with DE blowing into my pool. I have a 48 foot Hayward filter. I know it happens when the filter is on. I replaced the elements as they were old and I thought this was it. When I replaced the elements, I noticed some small cracks in the manifold. First I used marine epoxy on the cracks. When this did not stop the DE leak, I replaced the manifold. It still leaks. Before I go in and replace the o-ring on the inside pipe to the manifold, is there anything else it could be? Could it be the multiport valve?
One last thought. I read somewhere that you should only tighten the nut on the rod that holds the manifold to the elements slightly. I tightened it some more after the last breakdown but this did not seem to help. Maybe I didn't tighten it enough? Is there any way to tell when it is tight enough? I could use any thoughts or help anyone can give. Thanks.