What is this salt-like residue?

[new-to-poolcare]

I noticed a clear, salt-like residue on the skimmer basket and on the parts of the Polaris pool cleaner. After running the Polaris today, the all-purpose bag had collected a lot of debris that looks like a whitish sludge with some yellow in it. Can you tell me what it is? Thank you.

Here is the IMG code for a photo:

 

[Casey]

I have no idea what that is. Do you have any plants in bloom?

 

[JamesW]

Possibly calcium carbonate (marble) aggregate from the plaster if it's white marble plaster and it's beginning to deteriorate. Confirm by putting some in acid to see if it bubbles.

Possibly DE. Perhaps by bypassing the filter. Confirm by adding one cup DE into the skimmers and watch the returns for one minute to see if any comes back through.

Maybe DE backflowing through the main drains and skimmer due to an air leak at the multiport, filter or return lines. Confirm by checking for DE collecting at the bottom of the skimmer and/or around the main drain.

The color might be from iron or algae. Confirm iron by putting ascorbic acid on a yellow spot to see if it clears. Confirm algae by brushing yellow spots and watching for yellow clouds.

Possibly scale. What are all of your chemistry readings? Does the residue brush off easily or is it adhered to everything?

What is the texture and consistency of the substance? Is it a very fine powder, like DE, or is it a more granular material, like sand?

 

[new-to-poolcare]

Does the residue brush off easily or is it adhered to everything?

I first noticed it adhering to the Polaris hoses.

What is the texture and consistency of the substance? Is it a very fine powder, like DE, or is it a more granular material, like sand?

It is a granular material, like sand, but it is white like small, salt crystals.

At this point all I know is I had brushed off yellow algae using a stiff wire brush (recommended by the local pool supply store). After testing the water, I filled the nearly empty floating chlorine dispenser with tablets and added muriatic acid. The plaster is indeed old. I do not have all of the chemistry readings yet.

 

[JamesW]

I would suspect that you have multiple issues happening simultaneously. I think that the granular material is probably marble aggregate from the plaster. Put a drop of muriatic acid on some to see if it bubbles.

I think that the color is probably from algae.

You might also have de in the mix.

 

[new-to-poolcare]

Thanks for your input. The answer in a nutshell is calcification which eventually shut down the pump. The pool will need to be partially drained.

 

[new-to-poolcare]

Bad news. Here are the test results from the local pool supply chain.
Before the partial drain (no mention of testing for Nitrates)-
FAC: 2
TAC: 2
CA hardness: 1,000
CYA: 120
TA: 200
pH: 7.6
Copper: 0
Iron: 0
TDS: 4,500
Pho: 1,500

12 days later. After the partial refill and filter clean (once again, no mention of testing for Nitrates)-
FAC: 1
TAC: 1
CA hardness: 1,000
CYA: 120
TA: 160
pH: 7.6
Copper: 0
Iron: 0
TDS: 2,200
Pho: 1,500
Temp: 65

13 days later at a different location of the same chain. After adding 257 oz. of Muriatic Acid (14.5% HCL) 1 qt. 13 oz. at a time as recommended by the store to reduce TA and not seeing much of a reduction with my strip tests. (This time the salesperson told me she would test for Nitrates). She said the Nitrates were 120ppm and I must drain and refill again. She said fertilizer or fumigation would be the cause. I told her the neighbors fumigated their entire house recently and she said that ruined my pool.

FAC: 3
TAC: 3
CA hardness: 1,000
CYA: 200
TA: 150
pH: 7.8
Acid Demand: 2
Copper: 0
Iron: 0
TDS: 2,600
Pho: 300

Am I forced to completely drain and refill? Thanks.

 

[bdavis466]

There are several huge inconsistencies and downright impossibilities with your test results from the pool store. You need to get your own test kit and do all of your own testing. No advice can be offered based on what I have seen as those results are not even possible.

An example, in the last post you say you added 2 gallons of acid and still have a pH of 7.8? Unlikely unless your pH and TA was off the charts high.

The CYA level went up?
TDS went up?
CH was unaffected?

Calcification was the cause? There was enough scale to cause the pump to seize?

 

[Swampwoman]

Am I forced to completely drain and refill? Thanks

Hi there. While if your cya is truly 120 and your calcium 1000, yes, it is likely you will need/want to drain at least a portion, eg. 50% to get your water to a trouble free place.

But before expending the time and energy, please consider adopting TFP maintenance methods to optimize your efforts

1. Purchase either the tft100 or Taylor 2006 test kit (TFTestkits.net ) so that you can accurately test your own water parameters, especially cya, which can't be tested with other kits

2. Have a read in pool school on water balance and get familiar with the cya-FC ratio...its a short learning curve but will help you master this quickly

3. Sanitize with liquid chlorine/bleach instead of using trichlor pucks...those pucks add excess cya which then causes interference with sanitation...they're handy for vacations, but otherwise left out o your pool as they cause a moving target via the constant addition of cya with ever nailing the correct FC level.

By adopting this approach, you will be able to get a fresh start on your new-to-you pool and be in a better position to troubleshoot if your source water is high in calcium, his approach will help you read and manage the higher calcium levels to avoid degrading your surface etc.