Nice to be back, this site helped me several years ago.

[michael3]

I used to have an account a few ago, this site helped with the change from bauquacil to bbb. I am currently running a hayward s200 sandfilter with a hayward powerflo ex pump on a 24 foot agp. Everything was fine last season, this year on opening, water was very green, I bleached and bleached and its now cloudy. My problem is my return flow to the pool gets very weak, so I backwash the pump for up to a minute, rinse, and filter. Water return to pool is good for a short while then weakens again. I changed sand, it was nasty. After sand change, I was careful to add water first and slowly add sand to protect laterals. I put pump on backwash and Im blowing a ton of sand out my backwash. I rinsed and then am now on filter. Same problem, I got good return to pool for awhile then it gets very weak. I can turn off pump for a second and plug back in and get good water flow. I am baffled.

Sorry for the long post, but in short my issues are:
1. Why is my new sand blowing out backwash
2. Why is my water return to pool getting weak so fast

[michael3]

Anyone have any ideas? we didnt inspect the laterals because everything was fine last season, 3 local pool stores today said it sounds like a lateral problem. I have the water on recirculate right now, pressure is fine.

[PoolDoc]

Sounds like:

1. You have excess flow on backwash and are blowing the sand out of the filter. (Pump too big?)
2. You have filterable algae and it's clogging the filter. Kill it first, with lots of chlorine and it may filter more easily.

Bad laterals cause sand to leak into POOL on "Filter"; they do not cause sand to leak OUT on "Backwash".

[michael3]

Thanks, Ben
I have noticed that the sand only blew out on initial backwash after adding the new sand, so maybe it wasnt settled down or perhaps maybe alittle to much sand? any ways it has quit doing it lol. The filter is running longer and longer without losing water flow pressure, maybe it is just that nasty. One thing I`m not sure of, I know there isnt any cya in the water or its very low, with the amount of backwashing I`m doing should I worry about adding that right now?

[PoolDoc]

Yes, losing sand on FIRST backwash could have been overfill, OR sand spilled into the tubing.

If you use dichlor (Sams Club is the best source -- EVERYbody else sells blended or diluted dichlor) you'll be adding chlorine and dichlor.