10 PSI Hayward Pro Grid is that okay or low?

[beantownace]

Hello all. So I backwashed my hayward de 3620 filter this weekend that was running about 19 PSI for about 3 minutes and it cleared a bunch of brown stuff out and was clear. PSI dropped significantly to about 10 and then yesterday it was really low at 6. I cleared the skimmer baskets and main filter catch. I missed adding DE which was a big mistake but did it this AM. So far knock on wood not seeing anything coming out of the returns so hoping I am okay there. Does anyone know is 10 PSI okay or too low and if its too low what should I check or call someone in to take a look at it? Water looks good nice and clear overall.

 

[440dodge440]

I have a Hayward Pro Grid- runs 7.5psi after a backwash.

 

[beantownace]

Thanks Dodge made me feel a little better about it. The pool was opened before I bought the house in early July so I am hoping missing the DE for a few days with the filter running didnt do too much harm to the grids. I live in the Northeast so not a lot more pool time anyway but want to learn the ins and outs. I guess I will backwash once it creeps back to 18 or so. Tx

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One other question Dodge I see you have a vinyl pool very close setup as me it seems. Mine is 18k gallons. Do you add calcium to it at all? I have been reading dont need it but I do have a aquacal heater so wondering if I should put a little in?

 

[440dodge440]

I do not add calcium, and I don't have a heater, so unfortunately I'm not able to help at all on this....maybe someone else can join in or post it as a new topic.

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Many on here recommend backwashing when filter pressure increases 25%, which would be 12.5psi for you...The pressure increases will slow down as the water gets cleaner.