Knowing that it's never been cleaned since I bought the house/pool over 5 years ago and likely not for many, many years prior, I decided to deep clean my Baker Hydro HRV30 sand filter. My filter has the plumbing in/out on the side and the valve (a Hayward "SP715 ALL" multiport) sits adjacent, between the filter and pump. I was able to get the top of the filter off and work my hand in around the diffuser that blocks most of the opening and worked my way thru the sand with my water hose thoroughly. I'd read about channeling in sand filters but mine was literally clumped. So I gently worked my fingers thru as much as I could reach and probed carefully with the hose to try to break up the sand. All was going pretty well, although I didn't see a lot of debris washing out and I could definitely feel a fair bit of small twig-like debris in the sand.
But I failed to consider the valve, so you can guess what was happening all this time... a fair bit of the brown, strirred-up waste water was working its way back into the pool. It's taken me 3 days to clear up the mirky mess.
I'd like to take another run at deep cleaning the sand to try to float out more of the debris, but what setting do I need to move the handle on the multiport valve to ensure that gunk I'm dislodging in the filter can't back into the pool?
And, is there a point where the sand is so corrupted by debris that you hafta consider replacing it? The opening of the filter is obscured by the diffuser so I really can't see down in there, but it feels like there must be a lot of foreign matter in the sand. Also worth mentioning that when the timer kicks the pump on, there's usually a small dusting of very fine sand or silt that shoots out of the 2 (of 4 total) returns nearest to the pump.
On that Baker sand filter, does anyone know how to remove the diffuser to have better access to the sand? Just opening the thing up was a fairly bold step for me! This filter is extra intimidating because of the additional interior plumbing bits that are not typical of the sand filters with top-mounted valves featured in the YouTube videos.