First summer with a pool - think I have algae...

ddurrett896

Active member
Jul 16, 2018
43
Virginia Beach, VA
Installed a 20x40 salt pool last fall and this is my first summer using. Pools get full sun sun all day and below are my numbers - 100% test in range according to Leslies.

Chlorinator was set to 70%, just turned to 80% to see if anything changes.

I do have the Taylor Service Kit K-2006C, however I opened it and saw all the bottles and closed it back up since Leslie's is a 5 minutes golf cart ride away.

Noticed a little green around the liner corners that would brush off easy and almost look like a cloud of dirt when I pushed it. Also, my white skimmers would turn a tint green. I looked at the SLAM method, but the algae doesn't look that bad. The water is clear and no other swimmers have noticed. Is there something I could try first, before I have to SLAM my pool and take it out of commission for 4-6 days? Thanks!!

Free Chlorine (1-4PPM): 2.5ppm
Total Chlorine (within .2 of FAC): 2.5
pH (7.2-7.8): 7.6
Total Alkalinity (80-120ppm): 100
Calcium Hardness (200-400): 210
Cyanuric Acid (50-100): 50
Iron: 0
Copper: 0
Phosphates: 0
Salt (2,700-3,400): 2,700 from the store but my OmniLogic says it's 3,075 and rep said that's the more accurate reading.
 
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Sounds like you have algae and you'll need to perform the SLAM Process to get rid of it. You may be able to live with a bit of green, but you'll have to overwork you expensive SWG to keep up with chlorine demand.

In order to complete the SLAM process you'll need a TFP recommended test kit. Pool Store tests can't be trusted. Take a look at the link below and scroll down to the section on test kits. The kits from tftestkits.net provide the best value. You'll need the salt test kit option as well.

In the meantime, make sure your pool gets 3-4 ppm of FC daily. When you have your kit and you're ready to start the SLAM, come back and post if you need assistance.


Best wishes!
 
Sounds like you have algae and you'll need to perform the SLAM Process to get rid of it. You may be able to live with a bit of green, but you'll have to overwork you expensive SWG to keep up with chlorine demand.

In order to complete the SLAM process you'll need a TFP recommended test kit. Pool Store tests can't be trusted. Take a look at the link below and scroll down to the section on test kits. The kits from tftestkits.net provide the best value. You'll need the salt test kit option as well.

In the meantime, make sure your pool gets 3-4 ppm of FC daily. When you have your kit and you're ready to start the SLAM, come back and post if you need assistance.


Best wishes!
Thanks for the info! I did add to my post that I have a Taylor kit but my waters been clear and my quick Lelies test has came back good most of the time so I haven't started the learning process with the kit.
 
I do have the Taylor Service Kit K-2006C, however I opened it and saw all the bottles and closed it back up since Leslie's is a 5 minutes golf cart ride away.
Thanks for the info! I did add to my post that I have a Taylor kit but my waters been clear and my quick Lelies test has came back good most of the time so I haven't started the learning process with the kit.
You have an awesome test kit; take advantage of it. Pool store tests will only confuse things. Get familiar with your kit. Take the time to read the TFP's test kit directions in detail.


Test kits are expensive, so here are some testing tips that may help you conserve reagents and achieve accurate results...
  • Get a sample bottle with a dropper style tip. Leslie's has nice ones they'll give you for free.
  • Always rinse sample vials with pool water before and after use. With small sample sizes, even a bit of fresh tap water can skew results
  • When using droppers, keep the bottle vertical. Squeeze only enough to allow the drops to just fall off the tip
  • Go slow between drops (about 1 second between) and watch closely for color changes. On most tests, color hues are less important than determining the "endpoint."
  • The endpoint for most "count the drops" type tests is when there is no more color change. Keep adding drops until there is no color change. Don't count the last drop that results in no color change
  • For the first few tests, wipe the tip of the R-0009 TA bottle between each drop with a damp rag to eliminate static charge
  • Use 10 mL sample size for FC/CC test (R-0870/R-0871/R-0003 reagents)
  • Use 25 mL sample for TA test
  • Use 10 mL sample for CH test
  • For some tests, swirling is critical to achieve accurate results (there's a tool for that). Keep swirling the vial throughout the test.
  • Get that tool when your budget permits. You'll be glad you did.
  • Try to develop a routine and stick with it. Do the tests the same way each time.
Visible algae usually means a SLAM is required. You can complete an Overnight Chlorine Loss Test to confirm the presence of algae. Make sure you brush the pool before the test and shutdown the SWG between the two tests.
 
Thanks for the help! Just used my Taylor test to determine...

Free Chlorine: 2.5
PH: 8
CYA: 35

Downloaded the Orenda app and it says I need...

Decrease PH from 8 to 7.2 with 67.24oz of Muriatic acid
and
Increase PH (SLAM) from 2.5 to 20ppm with 551oz of liquid chlorine recommended by a family friend that does pool. The CYA chart says that with a CYA of 35, I need 14 PPM or 362oz of chlorine. Am I reading that right that I only need to get to 14ppm?

I'm going to buy my supplies now and the SLAM says PH needs to be 7.2. Can I dump the muriatic acid and liquid chlorine at the same time or do I need to lower the PH then add the chlorine later.
 
If you're sure you have algae, follow the SLAM Process. Read the instructions carefully. I'm not sure what the Orenda app is. We can provide advice based on PoolMath recommendations

If your CYA test landed between 35-40 ppm, round up to 40. SLAM level for CYA 40 is 16 ppm. Test frequently. Sun and organics will burn off FC quickly.

You can add LC and MA about 10-15 minutes apart.
 
If you're sure you have algae, follow the SLAM Process. Read the instructions carefully. I'm not sure what the Orenda app is. We can provide advice based on PoolMath recommendations

If your CYA test landed between 35-40 ppm, round up to 40. SLAM level for CYA 40 is 16 ppm. Test frequently. Sun and organics will burn off FC quickly.

You can add LC and MA about 10-15 minutes apart.

Just downloaded app to compare and under the sanitizer (Bleach, Trichlor, 48% Cal-hypo, etc), what would this liquid chlorine be considered? Thanks!

 
Dumped the required 4 gallons and FC shot from 2.5ppm to 17ppm....target was 16ppm based on 30K pool but I might be closed to 28K and my water is a little low right now.

Tested this morning using the 10ml (I went thru some 0871 last night using the 25ml at17ppm lol) and at 15ppm...still pretty close. Dumped the needed 38z of LC to bring levels back up.

Question: How quickly does the pools FC change after adding LC? Thanks!
 
Question: How quickly does the pools FC change after adding LC? Thanks!
It varies. Safe bet is to wait an hour with the pump running.

A loss of ~2 ppm isn't bad. Keep it up. It may take another day or two. Don't rush it. You want to eliminate it once and for all.

Although it doesn't sound like you have mustard algae, take a look at this article for seeking out hidden algae. Check in the seams of the liner, behind skimmer doors, under ladders etc.


Good luck!
 

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It varies. Safe bet is to wait an hour with the pump running.

A loss of ~2 ppm isn't bad. Keep it up. It may take another day or two. Don't rush it. You want to eliminate it once and for all.

Although it doesn't sound like you have mustard algae, take a look at this article for seeking out hidden algae. Check in the seams of the liner, behind skimmer doors, under ladders etc.


Good luck!
Appreciate the link!

I couldn't figure out if it's mustard or regular algae...just that it's green and when I brush everyday, it stays at bay. I left for 4 days and when I came back, it was pretty bad.

So my SLAM is 16. I added the required amount per pool math and this is where I am...

Day 1: 17ppm
Day 2 8:22am: 15ppm - added 38z of LC per pool match app
Day 2 11:00am: 16ppm - no action
Day 2 2:30pm: 12ppm - I did add 90 minutes of water since I backwashed and water level dropped close to skimmer bottom. Added 153z of LC to get back to 16ppm
Day 2 7:45pm: 12.5 ppm.

Surprised the 153z at 2:30pm only bumped me up .5ppm when I should have been at 16ppm. I do get full sun and must have brushed my pool 8x today and not seeing the cloud of algae lift off the floor like I did in the past.

Question: I planned on retesting again at 9pm tonight. That number (should be 12.5ppm) would be my overnight test base. Then I could test in the AM with the hope im between 11.5 and 12.5 (less than 1ppm drop overnight).

Does that work, or should I add more LC to get back at 16ppm then use that as my base? Only issue with brininging back to 16ppm is that I'm going to have to retest at like 10pm. Thanks!
 
Question: I planned on retesting again at 9pm tonight. That number (should be 12.5ppm) would be my overnight test base. Then I could test in the AM with the hope im between 11.5 and 12.5 (less than 1ppm drop overnight).
Throughout the SLAM, keep FC level at/above 16 ppm. I wouldn't leave it at 12.5 overnight. Dose, wait 30-60 mins, then test.
Surprised the 153z at 2:30pm only bumped me up .5ppm when I should have been at 16ppm.
Liquid chlorine bottles/boxes have a 5-digit date code (Julian date). Maybe you had an old batch. First two digits are year, last three are day of that year (example 22 060 = 60th day of 2022). If it's more than a couple months old, find another bottle.
 
Good idea going with the SLAM. Keeping FC at 16 will make it go the quickest. BTW, you can still swim. No reason to shut down the pool.
 
Throughout the SLAM, keep FC level at/above 16 ppm. I wouldn't leave it at 12.5 overnight. Dose, wait 30-60 mins, then test.

Liquid chlorine bottles/boxes have a 5-digit date code (Julian date). Maybe you had an old batch. First two digits are year, last three are day of that year (example 22 060 = 60th day of 2022). If it's more than a couple months old, find another bottle.
Done. I'll check it in 30 and use that as my baseline for tomorrow morning. Pool look clear and fine, just want to make sure it's 100%.

I did check the bottles and they were all manufactured in late May, so only about 1.5 months old.
 
Good idea going with the SLAM. Keeping FC at 16 will make it go the quickest. BTW, you can still swim. No reason to shut down the pool.
Really - my kids can swim? We we're eating dinner around the pool last night and one of my kids friends dipped their foot in the water and my wife grabbed her, ran inside and washed her foot off. Would have thought she touched nuclear waste. I was under the impression they could only swim when the FC is in range (3-7).
 
It's TFP's position that you can safely swim during the SLAM process as long as your FC doesn't exceed the FC SLAM level for your CYA and you can see the bottom of the pool.
 
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I was swimming in mine earlier this year with FC at 32 ppm. FC by itself is meaningless -- you have to consider the FC/CYA ratio instead. It's safe as long as FC is 40% or less than CYA.

FC/CYA Levels
 
Good to know - might let my kids jump in today after 3 days out. Just tested my OCLT and I would have sworn I'd be good but I'm not.

After SLAM (target is 16)
Morning Day 1: FC drops -2 from 17.0 to 15.0
Morning 2: FC drops -2.5 from 16.0 to 13.5

Brushed all day yesterday and not seeing signs of algae like I have in the past. Shallow end is crystal clear, 8' deep end seems a little cloudy, but I can see the bottom easy. Testing 5x/day and adding LC as needed per the PoolMath app. Is this typical? Only thing I can think of outside of the pool is that maybe my droplets of R-0871 for the test might not be uniform and throwing off my count. Thanks
 
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Yeah, it's typical. The last two I assisted on each took a week. Test frequently and maintain SLAM level. Monitor filter pressure. Backwash when you see a 25% increase over baseline/clean pressure.

Good luck!
 
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