Pool pump/filter flow problems

[pooldv]

Good that your FC is holding better, that is good progress. I don't know much about a sand filter, but there is a lot of info here:
http://www.troublefreepool.com/threads/73192-Deep-Cleaning-a-Sand-Filter

 

[duraleigh]

Generally, the filter body should be about 2/3 full of sand

 

[dloki]

I didn't measure it but it's 1/4 full or less I'd estimate, I think I'm going to clean it out tomorrow and replace it with 300 pounds of new sand. If I approach 2/3 full before I have 300 pounds in it I'll stop and see how the pressure through the filter looks. My pump seems to hit a wall at 20 psi and doesn't move any water so I need to be cautious of that. I think next year I will look for a new pump and filter setup, it's just not in the budget right now. The unknown manufacturer and specs of the pump and filter are making it a little more difficult to know what it should be vs what it is.

 

[dloki]

FC measured 26 this morning - possibly the difference between testing via flashlight and in sunlight?

Removed the sand from the filter, filled up 2 5 gallon buckets, replaced it with 300 pounds of new sand, first I added 200 pounds and reassembled the filter backwashed the new sand and tested the clean pressure, still measured 9 psi as it did before. Added the remaining 100 pounds of sand backwashed the new sand, the clean pressure looks to have gone up 0.5 psi but it's hard to tell with this gauge that is from 0 to 60 psi. I would like to get a better gauge but I learned last year this filter doesn't use a 1/4 or 3/8" pipe thread, possibly metric but I don't have any way to verify.