Replace filter system?

[jdelana]

I'm looking over my equipment after the lengthy time it has taken to clear my swamp. I used to drain my pool every year and refill. Water is cheap here. But my liner is on its 5th year and after reading advise here I decided not to take the risk of it tearing. My tests are fine but the water is cloudy and has been going on 3 weeks now. My pool is quite a bit too large for my filter system apparently. Thoughts?

TC 4
FC 3.5
TA 85
CH 150
PH 7.5
CYA 40

 

[Isaac-1]

When it comes to pool filters you get 3 basic options, sand filter, cartridge filter or DE filter.

Sand is the simplest to use, but requires the most water loss to backwash (an issue is you live where water is expensive or has restrictions on use) and in general does the poorest job filtering small particles.

Cartridge filters are sort of the middle ground here, cleaning is more hands on than sand filters, they tend to work a bit better than sand filters, and cost tends to be a bit higher.

This leaves DE fitlters which are generally the most work and at the same time do the best job of filtering, there are 2 basic types of DE fitlers, the tradtional tray models which can be very messy, and the Hayward Perflex models which use dangling membrane tubes coated in DE to do the filtering. I have one fo these Perflex filters and love it, there are also a lot of people around here that hate them, they do require a certain extra attention to detail, never allow the pressure to get to high between "bumping", thouroughly flush out when recoating, and weigh the DE when recoating, etc., but since switching from a sand filter my water looks oh so much better.

 

[jdelana]

Thank you for the information. I am more wondering if you guys here concur that my filter is too small and probably the culprit of my water taking so long to clear?

 

[linen]

Thank you for the information. I am more wondering if you guys here concur that my filter is too small and probably the culprit of my water taking so long to clear?

Yes that is a very small filter for your size pool.

The ANSI/NSF 50 Specification is about 266 sq.ft. for a 36000 gallon pool. Here we advocate 2X the ansi standard to limit cleaning to <2X/year (when not shocking) which would give a filter size of ~530 sq. ft.

By the way, are you sure about your pool volume, that 36000 would require that your average depth is about 6 feet?

 

[jdelana]

Pretty sure. 3ish in shallow and 8ish in the deep.

 

[linen]

Pretty sure. 3ish in shallow and 8ish in the deep.

Well if when you dose your pool with chemicals you get reasonably close to your goal, then it should not matter what I think :blah: ...but from my perspective, if the whole deep end was 8 (with no slope to walls) and the whole shallow is 3 (with no wall radius), and if truly half of you pool is at 8 ft deep, then that would be an average depth of 5.5 ft and poolcalculator.com gives me 32900 gallons...and I might guess it is even less once everything is worked out. :blah:

 

[jdelana]

Thanks for the advice. Picked up a new system Friday installed Saturday. Began filtration at 5:30pm. It was cleared up at 8am Sunday.

Really appreciate this site. Wish I would have found it 7 years ago! Not one pool professional has ever let me know about our undersized filter. We had 2 pool inspections before we purchased and used 3 stores. Oh and had a pool service company service the pool for the 1st couple months after we purchased. Charged $900 just to open the Dang thing. Jeesh!

 

[linen]

Glad we could help. Refresh my memory on what size your old cart filter was, since I see you have changed your sig to the new DE filter (that is the new one?).

 

[jdelana]

135 sq foot cartridge filter. About 5 times to small . It had been working for 3.5 weeks.

 

[linen]

Thanks for the update! I have a bad memory. Now that you have chosen a DE filter, keep that pool balanced correctly, DE filters can be "fun" to clear a pool with. Since they filter so well, they also plug up fast when you are filtering out dead organics.

 

[jdelana]

Thanks for the tip. I have backwashed once already. Probably have to do again this evening judging by the psi this morning. After that hoping it will be a much more infrequent duty.