Debris shooting from return jets

[OakMtnB&B]

Greetings all,

Up until now I have been able to sort all of my pool issues(inherited from previous owners) from the thorough resources available on this forum. No longer...I am officially stumped!!

I recently replaced my sand filter valve(new Jacuzzi Cantar Laser Sand Filter - DVK-7 Valve) and took the opportunity remove and replace the sand while it was open. All good afterwards-No more leaks, good pressure, backwashing/filter works well.

Here's the rub- I noticed after backwash/rinse/backwash that some sediment came out of the return jets when I switched back into filter mode. This stopped after about 15-20 seconds and all was normal again. Fast forward a week or so and before I back washed again, I simply turned off the pump for some reason and restarted it a few minutes later without moving the valve setting from filter mode. This time a lot more sediment came out of the return jets- pretty large plume actually but again subsided after about 20 sec. After reading similar post in this sub forum I made sure there was no sand in what was coming out of the jets, rather the sediment seems to be material that my automatic pool cleaner is sucking of the bottom of the pool(few small flower, buds, small insects, and some dead algae/dirt.

Any thoughts? This never happened before I opened the filter and changed the sand, but I was super careful and don't think I damaged any of the internal parts. I might have inverted some of the parts or not put back same way?? Could it be new sand settling in??

I'm perplexed!! Thanks for any suggestions!

Nelson

FC3
Cc0.5
PH 7.4
TA 100
cya 60

 

[Richard320]

Last thing before filter should be rinse. That gets any sand in the pipes into the right side of the filter.

Ideally, when you backwash, the sand bed gets all churned up so the lighter debris floats to the top and out. So it ends up in the "out" pipe as far as the backwash valve. When you rinse, things get sent the right direction and any stray bits of sand should end up on top of the sand pile.

From Deep Cleaning a Sand Filter

RINSE - ....rinsing. Rinse is exactly the same as filter, except the filtered water is sent out the waste line instead of back into the pool. This step should always happen after backwashing for two reasons. First, any dirt and debris in the filter that did not get ejected during the backwash is now in suspension with the sand. Immediate filtering could put some of it in the pool. Second, the rinse helps resettle the sand bed for when the system is placed back in filter mode.​

 

[OakMtnB&B]

Gotcha, thanks for that tip. I will add another rinse cycle.

What about other problem of sediment coming out of the return jets after the pump is turned off and then on again? Just to reiterate, in this scenario the valve is never changed from the filter position, but a large plume of sediment comes out once the pump is turned back on.

Thoughts??