Cleaning calcium buildup with wooden skewer?

[drewh]

Hi all,

Have mentioned in a few other posts my SWG cell builds up calcium deposit quite quickly (the pool CH level has generally been high - on the pool shop results so grain of salt!). Anyway, I normally use a 1:8 solution of water & muriatic acid and sit it in there to clean it. Often in spots there is still clumps of calcium particularly at the edges of the plastic frame.

I had a thought of using a wooden long skewer to nudge off the calcium, especially just after sitting it in the acid when the calcium is much easier to loosen, would this be ok? I know anything metal would damage the plates but the wooden skewer should be harmless?

 

[ping]

Yes, the wooden skewer should be fine to use, just be gentle with it.

You might want to try a stream of water from a garden hose with a spray nozzle before using the skewer. The last couple of times that I have needed to clean my cell, I soaked it in the water-acid mix and then sprayed it with the hose and it cleaned off the last bit of calcium.

 

[drewh]

Cheers for that ping, I'll do that tomorrow. A few times in the past I used a pressure cleaner but it was super messy though it did clean it well. I tried a spray nozzle hose once but the real hard clumps wouldn't budge (they sort of seem to build off the existing stuff so it gets harder to remove it).

How often do you clean yours normally? I reckon every 2/3 weeks mine is getting quite covered (esp the inner plates where the calcium was still there a bit from last time).

 

[ping]

I only have to clean mine every six months or so. I usually run my CSI a little negative and I have 50 ppm borates which helps keep the cell clean.

Post all of the chem levels and we will figure out what is the main reason for the scaling. I'm guessing that the CSI is positive and is causing the cell the scale.

 

[drewh]

I'm waiting on a TF-100 kit to arrive (I'm in Aus) but look forward to putting it to good use.. have a bit of an algae problem (see my other post) so will be SLAMing it to rectify that too. When I have the kit I will add the results on this post as well. Thanks heaps for your help ping - this is such a great community.

 

[malcolmb5325]

the calcium is attracted to your neg plates because it has an alkaline region around the plate as the ph increases the region becomes more alkaline which in turn attracts more calcium and the harder the calcium becomes, like coral sometimes. so keeping your ph at the lower end of the scale will have an affect on the build up. we have a few "salt cell softeners" on the market here down under so that can be another option but you are adding another chemical to the pool (mainly magnesium) which is an extra cost.

 

[drewh]

the calcium is attracted to your neg plates because it has an alkaline region around the plate as the ph increases the region becomes more alkaline which in turn attracts more calcium and the harder the calcium becomes, like coral sometimes. so keeping your ph at the lower end of the scale will have an affect on the build up. we have a few "salt cell softeners" on the market here down under so that can be another option but you are adding another chemical to the pool (mainly magnesium) which is an extra cost.

Malcolm thanks for the info, makes sense. My pH does tend to rise because there's a small leak somewhere in the suction line side as I see a few air bubbles from the return outlets and also in the chlorinator itself (tried everything to locate if it's above ground inc the pool school article but unfortunately looks as though it's somewhere from between the skimmer and the pump.

Are the salt cell softeners worth it? I have seen them at different places but have been skeptical.

 

[drewh]

Wondering if it might be better just to add borates as many at TFP pool do...

 

[Chuckiechan]

The new thinking seems to be advising against it and using white vinegar instead of muriatic acid.

I have good water pressure and am able to get most of it out with water alone, then vinegar for the more difficult stuff.

Bed, Bath, and Beyond (and other places) sell a hose attachment better designed for a concentrated spray if yours is weak.

The bottom line is these cells are so expensive, it seems the less you do the longer they last.

FYI, next year I'm also going with borates for better PH control.

 

[jblizzle]

The new thinking seems to be advising against it and using white vinegar instead of muriatic acid.

Who's new thinking?

Acid is acid. A diluted muriatic mixture could be no more harsh than vinegar.

 

[pooladdict]

^ Agree

 

[drewh]

I probably clean it in a solution of 1:8 muriatic acid and water maybe every month (and even then there's quite a bit of buildup), does this seem excessive to people? I do worry about the effect it will have on the cell long term though... The 1:8 solution is about 500ml acid to 4.5-5L of water.

The borates solution does seem a bit costly though - about AUD $155 ($8.75/kg here in Aus and I'd need 16kg plus the acid to balance the pH).

 

[jblizzle]

Borates are not guaranteed to stop the build-up if your CH is high and you allow the pH to climb too high.

 

[ping]

If you keep the CSI negative then the build-up should be minimal. Use PoolMath to calculate the CSI. Like Jason said, usually the pH and CH levels are high and that leads to build-up in the cell.

I have 50 ppm borates in my water and when I let the pH run in the 7.8 range I get build-up inside the cell. As my CH level keeps increasing, I have to keep a closer watch on the pH so it dosen't reach 7.8.

 

[prs]

I have 50 ppm borates in my water and when I let the pH run in the 7.8 range I get build-up inside the cell. As my CH level keeps increasing, I have to keep a closer watch on the pH so it dosen't reach 7.8.

ping, is the cell scaling because your CSI goes positive at 7.8, or do you get scaling at 7.8 even with a negative CSI?

I ask because I've recently found my ph stops rising at around 7.8-7.9, so I want to leave it there, my CSI is -0.30.

 

[ping]

My CSI gets a little + when the pH hits 7.8.

Now that the cover is on and I don't have to add fill water too often, I got my TA down to 60 for the last month and the pH has stayed at 7.5. I haven't added anything to the pool for a month now excecpt two inches of fill water.

 

[drewh]

Once I get the test kit on its way I will keep the pH lower & also make sure the CSI is slightly negative. Plaster pools shouldn't have a CSI that's too negative correct? Appreciate all the great help.

 

[ping]

Below -.6 is suspect to problems and above .6 is suspect to problems.

 

[Chuckiechan]

Who's new thinking?

Acid is acid. A diluted muriatic mixture could be no more harsh than vinegar.

Acid is acid as far as PH is concerned, but not all acids are the same. One can be used on a salad, the other can't.

I got the information here at TFP from a senior member's post. I used to use MA, and I have decided if I have to use acid again I'll use white vinegar. The reason given is that Muriatic acid can affect the coating on the plates, and white vinegar does not. If it makes my cell last longer, then I like it.

Maybe it's time for a chemist to settle the issue.