No suction on pool pump.

Came home from a trip and of course the pool was a disaster. My wife poured in way too much phosphate remover (I use the highly concentrated Orenda PR10000) which turns the water milky and coats the filter with a whitesh residue.
The pump was getting only a little water through it, but after I cleaned the cartridges it won't prime at all. If I put water in the pump basket from a hose the pump sucks it in and pumps it out through the pool outlets. If I put my hand up against the inlet inside the pump basket I feel powerful suction.
I was worried that the line between the skimmer and pump was clogged but I forced water through it using a submersible pump and the pool hose and the water goes through the pipe just fine.
I noticed that the gasket for the pump basket lid was missing. I suspect that this was a recent event. I temporarily fashioned a replacement but it made no difference. I need to go buy one today, but only one store has it and it's a long way away.
So my thoughts are:
1. The pump is faulty even though it will suck up any water that is put into the basket and I feel the suction. Maybe it's just not enough suction to suck the water up through the skimmer.
2. I need the proper gasket for the basket lid even though I didn't see any air leak.
Any other ideas?
I have a spare pump that I've been meaning to put in (a two speed) but I was putting it off as long as possible.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I put the chemicals in one application size containers when I go out of town. Does not prevent problems but does cut down on the incidents,
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.