Floc fail

[MikeSTL]

Trying to figure out the next step.

First a little history… Saturday we got trounced with 5” of rain in a very short period of time. It overwhelmed our gutters and drainage. It also overcame the pool deck grading and dumped a bunch of mud/dirt into the pool. It’s actually more of a light gray fine dirt of some kind. The stuff that’s on the pool deck actually feels a little powdery – a very fine dirt. I woke up Sunday to a solid gray pool with zero visibility. The filter pressure gauge was pegged all the way over (I think that’s around 50psi). I shut it down and attempted to let it settle. Ironically, the pool chemistry was still perfect. Apparently, this dirt brought in practically no organics with it. The filters didn’t really look that bad – until I started rinsing them. Wow, they were really loaded with dirt.

It looked a little better Monday (after 24 hours of calm settling time). So, I decided to try to filter this stuff out. I expected them to clog almost immediately. However, they never did. The pressure never built up. I guess the larger dirt particles that the filters were capturing before did actually settle to the bottom on their own. So, I think that part of my strategy was good. However, the pool wasn’t clearing. On Thursday I was considering a floc treatment since it has been several days with little improvement. So, I pulled the filters. This time there was very little dirt that was rinsing out. This is consistent with the pressure reading. So, obviously, the remaining stuff is too small to be captured by the filter. Again, the chlorine’s been holding this whole time. I did add what would normally be expected. So, the chemistry is stable. We aren’t dealing with algae. We are dealing with some kind of fine powdery dirt.

Thursday evening I decided to try a floc treatment. Based on the descriptions I’ve seen, it looked like too severe of a case for a clarifier. Besides, I have great options for vacuuming to waste. Even though we have cartridges, we have a waste diverter valve. But, even better, we have a siphon option as we have a hillside off the back of the pool. The siphon allows me to go non-stop even taking the water level well below the skimmers. This works great for opening as you don’t have to stop for any basket cleanouts. So, I figured I’m good in that department.

Thursday night and today (Friday) has been perfect weather for this. ZERO winds. Super calm. Only problem, the floc didn’t seem to capture any particles. The pool still looks the same. It’s been 24 hours now.

So, where do I go from here. I’m not expecting the pool to look any better tomorrow morning (36 hours after floc).

• Should I give it longer? And, how much longer? I’ve read 24-48 hours.
• Should I “refloc” and start the pumps for a couple hours and try again? I’m concerned that this dirt may be resistant to sticking to the flock.
• Should I put in a very old set of filters that I don’t really care about (I almost threw them out) and let it run with those and see what happens? I was planning on using these after the floc treatment anyway.
• Maybe above with a clarifier.
• Any other suggestions?

Unfortunately, the water is not clear enough to see any part of the bottom. So, vacuuming is not really an option at this point. Also, I would like to add a normal dose of chlorine. So, I’d like to run the pump for a bit. But, I don’t want to disturb the floc if I do need to let it work longer.

Thanks.

 

[JoyfulNoise]

Most flocculants require a very specific set of water chemistry conditions (pH and TA) to work right. Did you adjust your chemistry at all before adding the floc? Typical flocs are added around the perimeter of the pool with the pump running to get a good mixing and then you shut it down to let it settle. How much mixing did you do?

A better approach might be to get some filter fiber additive (Jacks Magic sells it) and the add that to the filter with the old cartridges. The filter fiber additive will help to capture the fines that are getting through. The filter will short-cycle when you’re doing that so you’ll need lots of time to baby sit it and clean the cartridges.

 

[MikeSTL]

Most flocculants require a very specific set of water chemistry conditions (pH and TA) to work right. Did you adjust your chemistry at all before adding the floc? Typical flocs are added around the perimeter of the pool with the pump running to get a good mixing and then you shut it down to let it settle. How much mixing did you do?

My ph=7.4, TA=80. The instructions said ph should be 7.2-7.8 and TA should be 60-120. So, I was in the specified range. However, I've since noticed that other products seem to recommend higher ph/TA. So, perhaps I should have erred more to the higher end of the spectrum. And, the instructions said to spread around the perimeter directly (do not dilute). There wasn't quite enough product to make it all the way around. But, I think it was good enough. And, then it said to circulate for 2 hours. Which I did a little more than that.

A better approach might be to get some filter fiber additive (Jacks Magic sells it) and the add that to the filter with the old cartridges. The filter fiber additive will help to capture the fines that are getting through. The filter will short-cycle when you’re doing that so you’ll need lots of time to baby sit it and clean the cartridges.

This morning there was a remarkable improvement. I could identify some leaves on the bottom. And, a few hours later, I can see that the bottom is really almost completely covered with mud with it looking extra thick near the point of entry. It's almost clear enough to vacuum in the shallow end (which is about 2/3s of this pool). And, I can see the beginnings of the ramp going down into the deep. So, it's looking like it's going to be closer to 48 hours. The package said "overnight".

I think I might try that filter fiber stuff after I vacuum. I'm assuming it's probably going to need some help to get it back to perfection. I've never had an incident like this. So, this kind of cleanup is all new to me. After each rinse-out of the filters, I assume I'll need to add more filter fiber? Or, does it remain stuck to the filters? Just trying to get an idea how that process will go and how much I'll need to get.

Thanks.

 

[JoyfulNoise]

The fiber aid should mostly rinse away with the dirt but it can load up the filter cartridges irreversible so it’s best to use the old ones and then toss them.

Flocculation is tricky business and requires a good deal of time to get right. Standard flocs based on aluminum or iron salts work better at higher pH. But it sounds like it’s starting to work. Don’t overdo it with flocs, adding too little is far better than adding too much.

 

[mgtfp]

I had to floc earlier this year after a dust storm from further north had rained down here (turned all of Melbourne's pools into mud ponds). Took about 2 days for the floc to settle and vacuumed to waste. Then I waited another 24 hours and had more gunk settling to the bottom, another vacuum to waste. After that, it stayed stable and I started circulating through the filter again. At the end of the swimming season (down under), I opened up my sand filter and gave it a deep clean. But the filter looked good, no goo, just the expected level of pine needles.

Normally, I would have tried filter fibre first, but it was the last week of the school holidays, and the bush-fire smoke had finally cleared, so we actually wanted to use the pool. So, I took the risk of going straight to floc, rather than going step by step. But it worked out alright.

Yesterday, I had a blockage in my Poolvergnuegen Pool Cleaner. Opened it up to (successfully) remove the obstruction. But while it was open, I realized that the inside of the cleaner was still covered in a thin layer of that extremely fine dust from January. Lesson learnt: Think about dust hiding spots!