Need tips for removing fine sediment from bottom of pool

[pfitz4]

I have a fine sediment collecting in the bottom corners of my deep-end, and in little piles on the floor of the shallow-end, near the return jet. It is brown/tan in color and looks like dirt. Could be pollen. It scatters and disappears when brushed or disturbed by the polaris. When manually vacuumed, it seems to go away but then reappears later in the day or the next day.

I also noticed that if the sediment is disturbed/brushed overnight when the water is not circulating, it does *not* resettle at the bottom in the morning. I run my pump 8-10 hours during the day, so it is off at night. But once the jets come on, the piles re-appear. Water is otherwise very sparkly.

My pool chemistry seems on track, although I have noticed that I'm having to crank up my SWG% to keep the FC where I want it, compared to last year.
FC - 4
CC - 0
pH 7.8
CYA - 65
TA - 90
Salt - 3000

Any tips on removing fine sediment from the pool?

 

[mknauss]

Normally the appearance of sediment that 'poofs' away means dead algae. Your SWCG is keeping it just knocked down enough.

Raise your FC to SLAM Level. Use 70 as CYA (you cannot measure a 65, the scale is logarithmic). Keep at SLAM level today and tomorrow and see how it looks. Try a Overnight Chlorine Loss Test Sunday night.

Take care.

 

[Richard320]

Algae. Kill it. The process is called Shock Level And Maintain. SLAM Process

 

[ajw22]

Your pool is a living dynamic outdoor environment, not a sterile surgical operating room. Stuff is constantly falling and growing in your pool which is why we need to keep it sanitized with chlorine.

There are often corners in a pool where stuff lays there. That is why we brush to stir the water.

 

[pfitz4]

Thanks I will follow your advice. I know there is no way around the FC level of 28 to properly SLAM. But will this cause my brand new liner to fade?

 

[mknauss]

As long as your CYA is 70, no. After adding LC at the return into the pool use your brush to move it around.

Take care.

 

[duraleigh]

But will this cause my brand new liner to fade?

Repeating what Marty just said, The CYA of 70 buffers the harshness of chlorine. Your liner will not fade.

 

[pfitz4]

Thanks! That gives me some peace of mind. Is it safe to swim with FC levels this high, or is it best to stay out of the water for a few days?

 

[mknauss]

You can safely swim in a pool with FC above minimum and at or below SLAM level. You also need to be able to see the bottom of the deep end of the pool.

 

[pfitz4]

Started the SLAM. Is it ok to leave the SWG on to help maintain the correct FC level? Or is there risk of damaging the salt cell or salt system?

 

[mknauss]

You won't damage it. We just recommend turning it off as it is not designed to add significant amounts of FC as needed for a SLAM and you are just using up its life.

Up to you.

 

[pfitz4]

I believe I passed the OCLT. My DPD powder is old, so my results may not be perfect. Refill is on the way.

I did two tests last night and two this morning, and all were within 2 ppm FC. Question 1 - Should in go ahead and let the FC drift down a little, then re-test when fresh test chemicals arrive?

Water is sparkly clear and sediment did not return after vacuuming.

Question 2 - is OCLT accurate only at SLAM levels or can it be used at any time?

 

[mknauss]

I would let your FC drop to maintenance levels.
OCLT is valid at any level. At higher levels of FC it can be problematic to meet the 1 ppm threshold as testing error can be greater than that.

 

[pfitz4]

Thank you for all the guidance!

 

[sccm_sysadmin]

I'll throw my hat in the ring and mention this: it might just be dirt that is piling up due to slight 'ridges' in the vinyl liner. I have this exact same thing -- small piles of dirt/pollen that falls to the bottom of the pool and collects where a few pieces of vinyl are attached together, probably less than 1mm tall. If this ridge is in an area with low flow, the dirt just can't make it up and over the ridge to get down to the main drain and be filtered out. My pool only has 3 return jets so there are a few dead zones that are right where these ridges are located.

My pool is right next to a wooded area (complete with branches hanging over the water). I get all kinds of stuff that gets in the pool, settles to the bottom when my pump isn't running, and then can't make it past these small ridges on my liner to get filtered out. I vacuum to waste every now and then and they're gone.

Maybe one of these days I'll try re-adjusting my return jets to see if that helps. My neighbors just had a pool put in and I swear that have 6-8 return jets. I bet that really helps cut down on dead zones.