Filter pressure will not drop after vacuumed some paving debris!

[Pins]

Hi all,
Fairly new pool install been up and running a few months. Pool spa combo. Recently I haven’t been able to get my sand filter pressure to drop back to the 85kpa that it always used to. I have backwashed a few times until sight glass is clear but now won’t budge below 150kpa on full speed.
I think this happened after I vacuumed debris from pavers into the filter which i thought would be ok to backwash out. Not a massive amount. There was very fine stone grindings and bits of mortar . Could it be that this has somehow bonded to the sand media and that’s why sight glass is clear even though it might be blocked up?
Also had infloor heads installed but I’m pretty sure the high pressure issue came after I vacuumed the paving debris to the filter. Would installation of the heads increase pressure?
The gauge does move freely and returns to zero when off.
thoughts? Thank you in advance.

 

[wireform]

Seems like you've invented a better filtration called sand/mortar combo. It's so good it won't even let water pass. I'd probably dump the sand and start over.

 

[Pins]

Thanks wireform. Hmmmm I thought that might be the case . Never done it before but sure there is info on here.

 

[Jimrahbe]

Pins,

Not sure what is used down-under, but here they use plyometric sand. Which turns into "concrete" after it gets wet. That is why they use it for locking pavers together.

Jim R.

 

[Pins]

Thanks Jim, yes I thought that perhaps if it was floating around in the water it would be able to be backwashed but I think somehow it’s bonded to the sand. Would agree next step is just to get the sand and change it all or is it worth opening first to have a look ? No idea what I’d be looking for, maybe wishful thinking there is just a solid object blocking something but realistically something like that can’t get through the hair basket anyway. You think it’s pretty clear the sand needs changing? That’s my gut feel.

 

[Pins]

So another question. The brochure for the filter lists three different media. They are Sand 60/30, glass pearl and zeo plus 2-2.2. Any thoughts, pros and cons? I dare not ring a pool shop .

 

[Jimrahbe]

P,

We always recommend just sand....

I'd wait until you get the filter open and see if anything is obvious...

Thanks,

Jim R.

 

[hwy17]

You could try just scooping out and removing the top layer off the sand bed, the problem is all likely at the surface of it.

 

[Pins]

Aah that’s really interesting. That would be great if it was just the top layer as certainly not cheap to refill the whole filter. As I’ve mentioned before, water saving is a big issue here in Melbourne and the glass beads are supposed to use less water for backwashing. For the moment I’ll inspect the filter and see if I can keep it running with sand but then down the track once everything has settled I’d be keen to switch to glass beads. Thank you.

 

[Pins]

I was reading that a restriction in the return system would increase pressure. My installer sounded surprised that the paving gunk would not have back washed. I’m wondering if there is a chance that the infloor heads have increased the pressure? Would it be expected that installation of infloor heads could double the filter pressure? The filter does seem to be working fine and pool is clean. Wondering if I should just keeping running it and if all is working well assume it is the infloor heads? What do you think?

 

[Jimrahbe]

Pins,

If the before pressure was without heads on your in floor system, and the after pressure was after they installed the heads, then yes, I'd vote for the heads being the problem.. It is just like putting your thumb on the end of a garden hose... I must have missed the IFCS system in your initial post.

Thanks,

Jim R.

 

[wireform]

That's like saying after patching a flat in a tire shop with a proper tire patch and the tire actually holds air now " wow no air leak" well that's to be expected isn't it , then I guess why are you so surprised that the mortar is restricting if it's actually working by design but unfortunately in the wrong place but then again who's fault is that ??
Is there a way to bypass the IFCS to see the pressure revert back somewhat.

 

[Pins]

Thanks both. My gut feel is the pressure increase happened before the heads went in after vacuuming in the gunk. But not 100% sure on that. Good idea Re bypassing the heads. I’ve messaged the installer to see if they have a sense of the pressure increase expected as maybe that’s it??? Not a big job to remove heads so maybe that’s an option too and see what happens. Thanks.

 

[Pins]

Also as encouragement to others, I’m happy to say I’ve just donated at Gold level. I can’t really benefit from the discounts but after trialing this forum and the Pool Math App I can see the amount of work that has gone into this system. Certainly easily worth the $USD100 even at our currency exchange rate! Super awesome to have experts to bounce ideas off.

 

[Pins]

It is holding steady at 150kpa so maybe it is just the heads and I just had my timing wrong, thinking it increased after the paving stuff was cleaned? In awaiting a response from pool installer but I guess it could feasibly double the the pressure going from open pipe to the infloor head? Let’s see if I get an answer from them that aligns with this increase before I pull the filter apart.