Chlorine causing problems with plastic

[bribri]

My CYA is at 70, I keep my chlorine around 6 but sometimes up at 11 (swg pool). When I opened this year my filter is letting sand into the pool and the 7 way valve is allowing water to drain when is set to recycle. It is an old Jucazzi Laser 190 With a Praher 7 way valve. My pool is 60,00 liter with a 3/4 hp pump. Could the high chlorine cause problems with the laterals and valve maybe causing the plastic and rubber to become brittle? I'm thinking about replacing it but I'm not sure size sand filter to purchase. I read somewhere that my pump might not move enough water to backwash a large sand filter. I'm OK with a sand filter but am also considering a DE filter. How many years do you get from a DE filter comparing it to a sand filter. Is the water that much clearer with a DE filter to off set the price?
Thanks, Brian

 

[maxepr1]

Sounds like the seal in that 7 way valve has failed. DE will clean far finer than sand, worth the price? It's up to you on price, to me it is. Some people don't like messing with DE, so it's up to you. Having had both, I would never go with anything but DE. Just the nature of being out in the elements and I supposed an un-balanced pool would help speed along plastic and rubber decay?

 

[maxepr1]

What model # is that valve? It probably has a spider gasket.

 

[JasonLion]

Chlorine can cause issues with some kinds of plastic, but no one in the pool industry would use those kinds of plastic.

What model of pump do you have? The HP rating is only suggestive of what size the pump is.

All of the different kinds of filters last about the same amount of time. Cartridge filters sometimes need cartridges replaced, DE filters sometimes need grids replaced. The rest of the parts, the housings pipes and valves, are really all about the same.

As maxepr1 said, the leak to drain is probably the spider gasket. That is a common issue and fairly simple to fix.

Some people can see the difference with a DE filter compared to sand right off, others can't see any difference at all.

 

[bribri]

The valve is a Praher model TM 12. Im sure I could replace some parts but I'm concerned about the sand passing through the filter when it is set to filter. Could a faulty valve cause this?
The pump is a Hayward Super Pump model C48J2N131B3.
If I opened the valve up would I see the problem. Which parts of a valve usually get replaced?

 

[linen]

The valve is a Praher model TM 12. Im sure I could replace some parts but I'm concerned about the sand passing through the filter when it is set to filter. Could a faulty valve cause this?
The pump is a Hayward Super Pump model C48J2N131B3.
If I opened the valve up would I see the problem. Which parts of a valve usually get replaced?

Maxepr1 and JasonLion is talking about the spider gasket which is part #13 on this page: http://www.prahervalves.com/pdf pool/Praher MPV manual.pdf see the second page exploded drawing. It is pretty easy to see if it is bad, and pretty easy to replace.

 

[bribri]

Thanks, cheaper then a new filter.
Could a faulty spider gasket cause sand to flow into pool when set to filter?

 

[257WbyMag]

Thanks, cheaper then a new filter.
Could a faulty spider gasket cause sand to flow into pool when set to filter?

I would check the spider gasket first. As mentioned, they are easy to replace if needed. The other reason that you may get sand in the pool is if you have a broken lateral in your sand filter.