Stain and/or Algae

[Paul Evert]

New pool owner here with a stain or algae problem. The pool is salt water, 7200 gallons and less than a year old. Several neighbors recommend TFP and I have been bingeing on it for two days. My pool service doesn’t know what is is and wants to drain the pool and acid wash it. I don’t think that is the right course to take based on research on this site and speaking with other knowledgeable pool owners. I had the water tested by a commercial pool company and tested it myself using the Taylor K-2005 Kit AND A ORAPXI salt tester. The readings were the same in both tests. Should I begin by adjusting the water balances and then SLAM it? Or is more work needed to identify what he stain/algae is?

Photos and testing results attached

Thanks,

Paul

 

[reggiehammond]

If your pool store testing results are correct, which they're likely not, you should fire your pool company.
Your pool is effectively unsanitized and can harbor harmful bacteria, viruses, etc.

Get a proper test kit, post up a full series of results, and prepare to use the SLAM Process.
An Overnight Chlorine Loss Test can confirm it's algae, but given how little FC you likely have, a SLAM is a foregone conclusion.

You may need to drain some water if your CYA is indeed ~80, but let's get a proper test kit first.

Once we get the pool water sanitary and clear of organics, can then deal with the stain (if it persists) after...

 

[kimkats]

Hi and welcome to TFP! You have an okay test kit for everyday use but it is missing one test you will really need to get the water clear and balanced. It is the Chlorine Test (FAS/DPD) - This test measures free chlorine VERY precisely, even up to 50ppm+. The Taylor FC test only goes up to 5 as do most pool store tests. That is not high enough to do a SLAM as seen in the link @reggiehammond

This test comes in the Taylor 2006 then you add an C on it and get more regents which you will need to do a SLAM. Now if you want to make sure you don't run out before we get rid of that black monster I would get the TF-1000 XL set.

I am SO glad you have your own test kit already. We just need to make sure you have all of the tests your are going to need to clean that pretty pool up!

Kim

 

[sande005]

Most here dislike any pool store tests. Your test equip isn't quite as good as is usually recommended, but if both the store and you are in agreement, then things are definitely wrong and you are growing bad things. Surprising your SWCG is not throwing an error with the salt so low. It likely is not generating much, if any, Cl.

Go to TFTtestkits.net and get their salt testing combo, at least. Get their Chlorine Test (FAS/DPD) combo, also. And their smart stir stirrer. Price out and see if it is worth it to just get one of their complete "Pro" kits, although it will duplicate some of what you have. Most digital meters are not to be trusted (salt or pH). But, if you and the store are in agreement....

Doing SLAM will not hurt things, and has a high chance of resolving the issue. So start there. Use the PoolMath app or charts here to figure out how much CL to add for the SLAM. It will be a lot, and continue to be a lot, because of your high CYA level. So stock up on the liquid chlorine. (Don't use anything else). If it is algae, as the SLAM starts to kill it, it will become easy to brush up. But that may take a few days to begin to see results. But make sure to brush very frequently, so the CL can get to the algae below the algae.

 

[Bperry]

New pool owner here with a stain or algae problem. The pool is salt water, 7200 gallons and less than a year old. Several neighbors recommend TFP and I have been bingeing on it for two days. My pool service doesn’t know what is is and wants to drain the pool and acid wash it. I don’t think that is the right course to take based on research on this site and speaking with other knowledgeable pool owners. I had the water tested by a commercial pool company and tested it myself using the Taylor K-2005 Kit AND A ORAPXI salt tester. The readings were the same in both tests. Should I begin by adjusting the water balances and then SLAM it? Or is more work needed to identify what he stain/algae is?

Photos and testing results attached

Thanks,

Paul

As mentioned above, you likely have algae growing because there’s almost no chlorine in the water. You have a decent test kit except it’s missing the FAS-DPD Chlorine test. I think you can order it separately as the k1515 or you can get a full kit in the TF-100 from tftestkits.org.

You don’t want to acid wash the pool unless it’s absolutely necessary as it reduces the lifespan of the plaster when you do it.

 

[Paul Evert]

I appreciate all the advice and will order a test kit today. It seems like the TF-Pro with SmartStir would be best in my current situation situation and future. Do I need any of the options: borates strips, Salt Strips, Standard Sampler, Ph Meter and SLAM Option?

 

[sande005]

I appreciate all the advice and will order a test kit today. It seems like the TF-Pro with SmartStir would be best in my current situation situation and future. Do I need any of the options: borates strips, Salt Strips, Standard Sampler, Ph Meter and SLAM Option?

No, not needed. Can't speak to the current version, but the pH meter I got never really worked dependably (apparently most affordable ones don't). Unless you use Borax, no need for that. the salt test will be better than the strips (which can be a convenience, but one doesn't usually need to test salt that much). SLAM option gives you more of what you are getting for CL - see how fast you go through things, you can always order more later.

 

[kimkats]

The SLAM option for sure to make sure you have enough regents to get rid of the black algae. The standard sampler might be helpful to help you learn how to read the CYA test but not necessary.

 

[sande005]

The SLAM option for sure to make sure you have enough regents to get rid of the black algae. The standard sampler might be helpful to help you learn how to read the CYA test but not necessary.

Well, up to you. My original 2 oz bottle and powder has lasted since the end of last year, and through the summer. The SLAM kit I got this spring, in anticipation, has never been opened. Probably will have to throw it to start fresh next year. tfttestkits says the stock amount is good for up to 140 tests (fewer if slamming), so not a biggie to order in a couple weeks if you do find you are blowing through it all quickly.

 

[kimkats]

We know they sre going to have to SLAM due to the black algae so might as well order now instead of later and have to pay shipping.

 

[Mdragger88]

You want the salt version of the tfpro or tf100 - this includes the salt drop test so you don’t need strips.
The tfpro also comes with the stirrer which is nice.

Until your kit comes get fc up to target range with some liquid chlorine asap so things don’t get out of hand
FC/CYA Levels

 

[Paul Evert]

The pool has come a long way since the last post and is 95% cleaned up. I wanted to hold the pool service accountable and fix the problem before I let them go. The owner has personally been here almost daily to test the water and use Jack's Majic products to clean up the algae and copper. I have performed my own daily testing to verify his readings. He determined his technician used mercuric acid to clean the walls along the backside of the tile. The acid ran down the wall and of course into the heater which added copper to the water. He is replacing the heat core/exchanger to eliminate the copper issue.

This is a summary of what has been done so far by the pool service:
September 28:
- PH was less than one, chlorine level of 10
October 2:
- Found copper and iron on the pool ledges
- Treated with Jack's Majic Purple & The Copper & Scale Stuff
October 4:
- Pool drained and refilled
October 6:
- Discoloration improved but is not completely gone
- Calcium level remains high >1,750
October 9:
- Pool drained gain in an attempt to reduce the calcium level
- Jack's Majic Purple & The Copper & Scale Stuff applied
October 10 - 15:
- Daily testing and chemical adjustments made to balance the water
October 19:
My Pool Math Test results
FC = 3.0
pH = 8.2
TA = 120
CH = 200
CYA = 10
SALT = 400 (none has been added since the pool was drained)
Temp = 71F
SCI = 0.59

The pool is greatly improved from where we started and I have attached current photos. The pool service has recommended doing one more draining with a light acid wash of 50% water and 50% mercuric acid and then balancing the water to the proper target levels. They are confident the recommendation will clean up the remaining issues.

My question Is the light acid wash an appropriate next step in this situation?

 

[Bperry]

The pool has come a long way since the last post and is 95% cleaned up. I wanted to hold the pool service accountable and fix the problem before I let them go. The owner has personally been here almost daily to test the water and use Jack's Majic products to clean up the algae and copper. I have performed my own daily testing to verify his readings. He determined his technician used mercuric acid to clean the walls along the backside of the tile. The acid ran down the wall and of course into the heater which added copper to the water. He is replacing the heat core/exchanger to eliminate the copper issue.

This is a summary of what has been done so far by the pool service:
September 28:
- PH was less than one, chlorine level of 10
October 2:
- Found copper and iron on the pool ledges
- Treated with Jack's Majic Purple & The Copper & Scale Stuff
October 4:
- Pool drained and refilled
October 6:
- Discoloration improved but is not completely gone
- Calcium level remains high >1,750
October 9:
- Pool drained gain in an attempt to reduce the calcium level
- Jack's Majic Purple & The Copper & Scale Stuff applied
October 10 - 15:
- Daily testing and chemical adjustments made to balance the water
October 19:
My Pool Math Test results
FC = 3.0
pH = 8.2
TA = 120
CH = 200
CYA = 10
SALT = 400 (none has been added since the pool was drained)
Temp = 71F
SCI = 0.59

The pool is greatly improved from where we started and I have attached current photos. The pool service has recommended doing one more draining with a light acid wash of 50% water and 50% mercuric acid and then balancing the water to the proper target levels. They are confident the recommendation will clean up the remaining issues.

My question Is the light acid wash an appropriate next step in this situation?

The latest pictures don’t show anything I can see. Maybe more visible in person. Acid washing reduces the lifespan of the plaster so up to you if it’s worth the trade off. IMO it looks no worse than my brand new replastered pool finish and I’m be surprised if it could get any better.

 

[Paul Evert]

I’m using a TF-Pro test kit. The Chlorine Drop Test instruction #5 instructs that the total of FC and CC should be recorded as Total Chlorine (TC). I don’t see a place to record the TC in the Pool Math APP. What am I misssing?

 

[ajw22]

Record FC and CC separately in PoolMath. You don't need to record TC anywhere. PoolMath can add it up.

 

[Paul Evert]

Record FC and CC separately in PoolMath. You don't need to record TC anywhere. PoolMath can add it up.

Is the total shown anywhere or is it nothing to worry about?

 

[ajw22]

Is the total shown anywhere or is it nothing to worry about?

Total Chlorine is meaningless.

If you want to know it just add the two numbers.

 

[Donldson]

Total Chlorine is not really a useful parameter, more of a holdover from older testing methods where FC and TC could be measured and CC was calculated from those.

The instructions are taken nearly directly from the Taylor kits which the TF-Pro was based upon. So the instructions to record TC are really a holdover of a holdover. No need to record it, FC and CC give you what you need to know.

 

[proavia]

We don't care about TC.
Just enter FC and CC in PoolMath.

Which chlorine drop test are you using - the OTO (R-0600) or the FAS-DPD (R-0870 and R-0871)?
The OTO test is basically only an indication that you have "some" chlorine in the pool. The FAS-DPD test indicates how much chlorine is in the pool.
Use the FAS-DPD test using a 10ml water sample and one rounded scoop of the R-0870 powder - the test is accurate to 0.5 ppm, which is more than close enough.

 

[Paul Evert]

Total Chlorine is not really a useful parameter, more of a holdover from older testing methods where FC and TC could be measured and CC was calculated from those.

The instructions are taken nearly directly from the Taylor kits which the TF-Pro was based upon. So the instructions to record TC are really a holdover of a holdover. No need to record it, FC and CC give you what you need to know.

Got it, thanks