sand filter / glass

thewoodlands

Member
Feb 2, 2010
10
I have a 34,000 gal gunite pool built 2 months ago. Have a sand filter with eco - glass in it. while backwashing, i get some glass out the backwash line. not everytime. I was told that this set up would give me very clear water and filter as well as a DE filter. Now builder suggest we just replace the glass with standard pool sand and pebbles, then use a clearifier when needed.

Any thoughts on this? Pool builder is going to replace the entire filter and is waiting on me to decide if i want glass or just sand.
 

PoolGuyNJ

TFP Expert
May 20, 2007
3,192
South Central NJ
Eco-Glass is a very good media, but expensive, and will last many years.

New systems often shoot out a small amount of media during a backwash cycle. Sand or glass, it doesn't matter. Unless you are converting from Baquacil or it's ilk, there is no need to change the media at this point. If it's getting in the pool, then something else in the filter isn't right and needs to be addressed.

FWIW, Eco-Glass should be backwashed when the pressure rises 5 pounds from the start point as opposed to 10 with sand.

Scott
 

thewoodlands

Member
Feb 2, 2010
10
Scott thanks for your reply. when they first set up the filter system, they put the wrong multi port valve and so the flow was reversed. apparently there is a different multi port for other filter systems. Anyway, when they turned the system on, it shot glass all in the pool. The guy vaccumed it up back into the filter, changed the multi port and said it was good.

question I have is should there be just peagravel and glass, or just sand and glass, or can there be a combination of gravel, sand, and glass? I would think the best combo would be peagravel and the rest glass.
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,880
Silver Spring, MD
It is the top several inches of media that do all the work. You can use pea gravel on the bottom (about 1/3 of the total) and the filter will be just slight more efficient and will filter just as well. Except in the very largest sand filters it is also fine to skip the pea gravel and use all sand or all glass.

I'm not sure what the point of mixing or layering sand and glass would be, but that can work also. For best filtering you would want to use 1/3 sand on the bottom and then 2/3 glass on the top.
 

PoolGuyNJ

TFP Expert
May 20, 2007
3,192
South Central NJ
Gravel is not recommended with Eco-Glass.

If they put the wrong MPV on, the laterals need to be cleaned too.

There is no reason to not reuse the glass. If there is a shortage, make them replace the shortage. I would not accept a sand with a gravel base as a substitute without getting the money you paid for the glass back. There is a substantial premium for the glass media. From what I understand, this was their mistake.

When I do a wet sand removal, I drain the tank by put the system in Rinse and blow blow out the water until only air comes out the tank's drain. Then I let it blow for a few more minutes to get more of the moisture out. Then I shop vac it out. It's a lot easier. The glass can be dumped on a tarp from the shop vac and put back after.

Scott