Filter Upgrade or new Pool cleaner

strickon

Member
Jun 7, 2013
6
I have a 23000 gallon pool. I am in south Florida and it is open year round. I have a pentair 520 cartridge filter with 4 giant cartridges. The pool is about 6 years old and I have replaced the cartridges once. I am finding that when things work the cartridge filter is fine. The problem is after a big storm or some other event that brings debris into the pool, the cartridges need to be cleaned. This would be fine if it were a once or twice a year thing, but it seems to be happening more frequently. It takes about 2 hours with the aquacomb to deal with that. If I get an algae bloom it could mean doing that multiple times in a short period while shocking.

I just had my pool deck pressure washed which brought a ton of dirt into the pool and now require me to open it up and clean those cartridges again. When I do, the pressure goes down to 4-6 psi when run at 40GPM.

I have been thinking about replacing this and going with DE as you can back wash the filter and would only have to break it down once a year. That would require a new multiport valve. I don't mind dealing with DE if it means I don't have to open that filter up.

I also have a suction side cleaner. I am thinking that I could get a new filter or I can get rid of the suction cleaner and go with an electric one. This way I am not putting dirt into the filter and maybe extend time between cleanings. Seems much easier to clean the pool robot than the giant cartridge filter.

It is also SWG so I know backwashing my require more salt and cya. Half the year I am finding I need to drain water anyway from the rains so I could use that time to backwash anyway.

I read all about the convenience of cartridge filters but it seems more work, especially when things go bad.

Is the new robotic cleaner a better investment or should I swap my filter?
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,001
Tucson, AZ
Well, first, a DE filter is going to clog up more quickly. AND back-washing really does not clean it out very well. I don't do it any more, just tear it down completely when required. AND you have the DE mess all over the place. I do not think you will be happier. I wish I had a 520sqft cartridge and will like eventually change to that.

I think your money would be better spent on ditching the suction cleaner and getting a robot.

There is no way your big filter should be clogging up as fast as you say it is. I would think if the chlorine was properly maintained, you should be able to get close to a year between filter cleanings.
What FC and CYA are you maintaining?
I am wondering if you don't already have a low level algae bloom.
Or I suppose it could just be that you are pulling a lot of dirt into the filter with your suction cleaner.
 

strickon

Member
Jun 7, 2013
6
I try and keep the fc around 6 and cya 70-80. I had just cleaned the filter after it going a few months and then we had someone come and power wash the pool deck and turned the pool to green soup. I just cleaned the 4 carts today and my pressure is back to the usual starting pressure. I do seem to have some trouble with algae as I notice it on some of the walls and tile. Could be circulation issues. I go through the full shock treatment with bleach raising fc to about 20-24. I get everything stable again and then inevitably run into some problem like heavy rains diluting the CYA and FC dropping. Seems to be somewhat of a constant battle. I thought about trying borates. Polyquat 60 seems to help prevent blooms, but I would rather not add anything. Also water temp is now around 90. I keep the aqua pure at 75% running about 14 hours a day.
 

sktn77a

Gold Supporter
May 16, 2010
1,153
Chapel Hill, NC
I think your filter should be fine if you can get the debris out with a net or a good cleaner. Robots have limited capcities so you will need to empty it out frequently after a big storm. With a CYA of 80 (I see you have a SWG) you will probably need a higher free chlorine (30+) to adequately SLAM the pool after a storm - that might be why you're having issues with algae blooms and frequent cartridge cleaning.
 

strickon

Member
Jun 7, 2013
6
Does not sound like you are fully completing the SLAM Process process if you just raise the FC level up once. So perhaps you have an eradicated everything?

You could always raise the FC a bit and do the Overnight Chlorine Loss Test to see if there is something in the water.
I just went through the slam process and raised FC up to about 30 multiple times over multiple says with constant brushing. I think I had a lingering problem with some minor green spots on the wall. I used a wire brush this time. I have diamondbrite I passed the oclt. The only issue I see is that every time I brush I get small white clouds. If I brush at night and come back in the morning and brush again, I get them. Not as much like at the beginning, but it isn't completely clean. This is with the wire brush. the nylon brush doesn't seem to do much. Is this suspended dead algae? New algae? calcium? Should I still be slamming until the brush doesn't pick up anything? Is this something else?

Thanks
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
43,001
Tucson, AZ
No way for me to know what you are seeing in the water. You could be just brushing up dust from the environment.

If you are passing all 3 criteria, then the SLAM process should be done.