Algae in my pool

mdkraft99

Gold Supporter
Jul 19, 2021
13
Pinckney, MI
Pool Size
30000
Surface
Plaster
Chlorine
Liquid Chlorine
Moved from here.
Hello everyone,

I'm new to the forum and already found a lot of great information! I'm responding here looking for assistance, hoping I can get some more great advice. Here's the algae issue I'm having, and details about my pool:

Pool:
- Inground gunite pool, free-form shape (like a "bottom-heavy" figure 8 or snowman), approximately 20,000 gallons
- Floor drain is sealed due to leak, skimmers working fine
- DE filter, chlorinated (in-line chlorinator), clear solar cover
- We live in Michigan, pool is open ~late-May - early-mid Sept

Algae issue:
- Earlier this year we had green algae (presumed based on appearance, I have not had this tested in any way to confirm, but I've had green algae in the past and this looks the same), treated with brushing, liquid chlorine, vacuum, backwash...cleared up, all good
- Last month we were out of town for about 5 days, didn't have anyone who could uncover our pool while gone
- We returned and I had green algae on the walls and floor (~66 - 75% coverage), but the water was not cloudy or green
- Over the past 3 weeks, I have (in this order): tested chemicals, corrected, brushed, shocked, treated with copper-based algecide (Banish), vacuumed pool....cleared up, but then returned on walls and floor, but again pool water was clear and not green; again tested chemicals (all were good) and brushed and vacuumed again, backwashed filter.....algae returned but lesser coverage, maybe ~50 - 60% coverage.....again tested chemicals, brushed, shocked, treated again with Bioguard Algae Complete + Pool Juice 911, vacuumed, backwashed.........improved, but algae returned, slower this time and only to ~33% coverage.......tested chemicals, took apart DE filter and cleaned each grid off completely and soaked in dilute muriatic acid for about an hour, brushed, shocked and tried Algae Complete again, vacuumed - this was yesterday

Throughout this past ~3 weeks, I have left the cover off, run the filter continuously (except for 2 or 3 days where I turned it off for about 12 hours overnight), I've brushed the pool probably ~10 times, and the entire time the water has been very clear (almost "TFP Clear" - which I love, very impressive) - other than when I brush and it clouds up a bit, but then clears up again.

Today, I went out to run the vacuum again, and green algae started coming back on the walls in some spots, but much lighter and less than it has been, maybe ~10 - 20% coverage.

I've attached a few photos as well, best I could get.

I've been working with our local pool store, and we've worked with them for the past 7 years since we bought this house with the pool. They have been very good and I trust them. But now, I'm just getting beyond frustrated because I'm not sure on next steps to resolve this...or perhaps this is the approach I need to take and it is just a persistent case.

From what I have researched here, the SLAM method appears to be very effective. However, given this is only on the walls and floor, and is improving, and the water has not been cloudy or green, I'm wondering if this is the right next step? Does anyone have suggestions or would you agree? Could this be something else I'm not considering? Any other treatments/techniques/advice would be welcomed - I'm just at my wits end and so frustrated about this, and don't want to go to "overkill" and have to deal with that (and I'm happy to compensate with a beverage of choice if I can figure out how to get it to you :)).

Thank you!

-Mike
MK Pool Algae-1.jpg
MK Pool Algae-2.jpg

MK Pool Algae-3.jpg
 
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mknauss

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May 3, 2014
51,248
Laughlin, NV
Pool Size
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Chlorine
Salt Water Generator
SWG Type
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Welcome to the forum!
You need to follow the SLAM Process. To do that, you need a proper test kit. I suggest the TF100 or the Taylor K2006C. A proper test kit is needed to get the accurate water chemistry results needed to follow the TFP protocols.

While you are waiting on your test kit, add 5 ppm FC worth of liquid chlorine / plain bleach to your pool each evening with the pump running. This will replenish the FC lost each day to the sun and also inhibit any algae in the water from growing further.
I suggest you read ABC's of Pool Water Chemistry.
 

PoolStored

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TFP Guide
Jun 24, 2021
2,777
Ashtabula, OH
Pool Size
30000
Surface
Vinyl
Chlorine
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CircuPool RJ-60
I am new here too, first year pool owner. I followed the instructions found in pool school to a "T." Picture below is what I have today. You can tell heads from tails on a quarter in the 9' deep end.

a) go to pool school and READ EVERYTHING.
b) repeat "a"
c) dump the pool store
d) stop dumping shock, copper-based algecide (Banish), Bioguard Algae Complete + Pool Juice 911. Go read:Recommended Pool Chemicals
e) "However, given this is only on the walls and floor, and is improving, and the water has not been cloudy or green, I'm wondering if this is the right next step?" YES YOU SHOULD SLAM! Get a good test kit as MKnauss indicates. NOW!
f)
repeat "a"
g) know your numbers and get on the SLAM.
h) repeat "a" and get ready for when SLAM is done. You will want to be ready to balance everything else. Don't do anything with any chemicals, other than liquid chlorine/bleach until the SLAM is done. Do not cheat on the SLAM rules: CC <=.5, OLCT <= 1, clear pool.
i) Do it now, you will be much happier.

1626713506184.png
 

mdkraft99

Gold Supporter
Jul 19, 2021
13
Pinckney, MI
Pool Size
30000
Surface
Plaster
Chlorine
Liquid Chlorine
Welcome to the forum!
You need to follow the SLAM Process. To do that, you need a proper test kit. I suggest the TF100 or the Taylor K2006C. A proper test kit is needed to get the accurate water chemistry results needed to follow the TFP protocols.

While you are waiting on your test kit, add 5 ppm FC worth of liquid chlorine / plain bleach to your pool each evening with the pump running. This will replenish the FC lost each day to the sun and also inhibit any algae in the water from growing further.
I suggest you read ABC's of Pool Water Chemistry.
Thank you so much for the reply, I know I need to get a proper test kit and start doing it on my own, that is next on the list. I appreciate the advice, I will work on SLAM process and in the meantime use the liquid chlorine. Thank you again!
 

mdkraft99

Gold Supporter
Jul 19, 2021
13
Pinckney, MI
Pool Size
30000
Surface
Plaster
Chlorine
Liquid Chlorine
I am new here too, first year pool owner. I followed the instructions found in pool school to a "T." Picture below is what I have today. You can tell heads from tails on a quarter in the 9' deep end.

a) go to pool school and READ EVERYTHING.
b) repeat "a"
c) dump the pool store
d) stop dumping shock, copper-based algecide (Banish), Bioguard Algae Complete + Pool Juice 911. Go read:Recommended Pool Chemicals
e) "However, given this is only on the walls and floor, and is improving, and the water has not been cloudy or green, I'm wondering if this is the right next step?" YES YOU SHOULD SLAM! Get a good test kit as MKnauss indicates. NOW!
f)
repeat "a"
g) know your numbers and get on the SLAM.
h) repeat "a" and get ready for when SLAM is done. You will want to be ready to balance everything else. Don't do anything with any chemicals, other than liquid chlorine/bleach until the SLAM is done. Do not cheat on the SLAM rules: CC <=.5, OLCT <= 1, clear pool.
i) Do it now, you will be much happier.

View attachment 356484
Thanks so much for the reply and advice, I appreciate it! Your pool looks fantastic, I have some work to do.
 

mdkraft99

Gold Supporter
Jul 19, 2021
13
Pinckney, MI
Pool Size
30000
Surface
Plaster
Chlorine
Liquid Chlorine
*ahem*. There 👆 I fixed it for ya. We get VERY invested in our folks. Even the newbs. You no longer go it alone. You have us now, and we got you.

Welcome. :)
That's awesome, I know I'm in the right place....THANK YOU! I've had this pool for about 8 years now, and overall I thought I was doing a pretty good job. I did read up on pool chemistry, and other good practices to follow....but still had been relying on a local pool store for testing and assistance. Overall they seemed pretty good, never "pushing" or trying to upsell, always answering questions......but clearly I could be doing more, and as I've researched this more, they are definitely more to service those who want the easier answers and treatments.....but truly owning and managing a pool takes more. I like taking the ownership and learning.....so clearly I'm in the right place. Hopefully I'll get to the point where I can help other members down the road.

Thank you again, much appreciated!

-Mike
 
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Newdude

Mod Squad
Gold Supporter
TFP Guide
Jun 16, 2019
18,178
NY
but truly owning and managing a pool takes more.
It REALLY doesn’t. It’s EZPZ once we undo the bad habits and shortcuts. Trust me it’s one of those things that people spend a small fortune on, and way more effort than they need to try and do it the ‘easy’ way, which is anything BUT easy.

Step one is wanting to learn. *check*. We will happily guide you until you are your own pro. :)

The test kit will seem like rocket science at first glance. It is the EASIEST thing ever if you just give it a try. Click on link below. 👇
 

PoolStored

Gold Supporter
TFP Guide
Jun 24, 2021
2,777
Ashtabula, OH
Pool Size
30000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-60
Took me 6.5 days to SLAM my pool. Could do in 4.5 days knowing what I know now (given same pool). If my CYA wasn't so high, I could do a slam in 2-3.

Generally, do what I said above.

Specifically, here is my advice:
1) Get a good kit as recommended above.
2) Calculate your pool volume. Lots of calculators online, or LxWxD.
3) Test your CYA. It is a harder test to do, but don't fret. Just keep adding water to each line and look for the dot. If you can see at 50 and can't see at 40, then your level is 50. Don't make it more complicated that that.
5) If your CYA is 60 or below, skip to #9
6) If your CYA is 70 or above, you will need to exchange water. a) use the PoolMath or online calculator here Online Pool Math. Enter your pool size, current CYA and a target of 40 or 50. I used 40 as my target because it is easier to add a bit of CYA, than to drain and refill more.
7) Once you know how much to replace and how big your pool is, read this: Drain/Refill. I used a sump pump with a valve on the outlet to match the amount of water added from my hose. Took me 2.5 days to replace 13,567 gallons in my 36K gallon pool. DRAIN AND REFILL NOW.
8) RECHECK YOUR CYA. If 60 or below, good to go!
9) Check your pH. If it is between 7.2 and 7.6, you are good to go. Go to #11.
10) If your pH is high, or low, use PoolMath or the calculator to get suggesting for adjusting. Adjust.
11) NOW you can check for FC. Use the FAS-DPD Chlorine test now from your kit.
112) Follow the SLAM process--> SLAM. Use this chart FC Level for SLAM with your NEW or Original 60 or below CYA number to get your target FC. Use PoolMath or the online calculator from above. Enter your current FC and your TARGET SLAM FC. It will tell you how much Chlorine to add. Add it! Check FC and Add often! Every 2 hours is best. Every hour is not necessary.
13) This is what I found works QUICK.
A) You must scrub EVERYTHING. OFTEN!!! Lights (remove them and scrub backside). Took me 4.5 days to SLAM because I didn't realize the inside of the tubes of the ladder might have algae. My OCLT was 2.5 for three days, no change. Took ladder out and cleaned it, BAM, OCLT < 1. Clean EVERYTHING and scrub the pool when you add Chlorine.
B) I tested FC EVERY 2 HOURS and added Chlorine EVERY 2 Hours during the day. You MUST keep the FC up to your target if you want the process to go fast. Take the weekend. Do it. It is worth it. If you go to work and let pool go 8-10 hours, SLAM will still work, it just might take a week or two.
C) Ignore everything else during SLAM. Do no other testing. Add nothing but Chlorine. NO POOL STORE, NO POOL STORE CHEMICALS. Nothing matters but the SLAM.
D) When and ONLY when you meet SLAM criteria. SLAM for one more day. Great insurance.
E) TRUST THE PROCESS DO NOTHING BUT SLAM.
14) After your SLAM, you can adjust everything else. The only other thing I had to adjust was my TA. It was about 140. I made an aerator EXACTLY like this: aerator pic. I put it on the sump pump I bought to drain the pool. I added muriatic acid to reduce pH to 7.0. Aerated for 12 hours. This would reduce TA by 10 points, and raised pH by .2 to 7.2. The muriatic acid reduces pH and TA. The Aerator increases pH without adding any chemicals. Took me ~3 days to get it to TA 70. pH increases the most at 7.0-7.2 because of outgas rate is higher at these values.

Now everything is great. I add chlorine and that's about it these days. I added borates (do a search), but is optional. I like the look and my pH is super stable.

It is simple, but takes work to get it done. Good luck!
 
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mdkraft99

Gold Supporter
Jul 19, 2021
13
Pinckney, MI
Pool Size
30000
Surface
Plaster
Chlorine
Liquid Chlorine
Took me 6.5 days to SLAM my pool. Could do in 4.5 days knowing what I know now (given same pool). If my CYA wasn't so high, I could do a slam in 2-3.

Generally, do what I said above.

Specifically, here is my advice:
1) Get a good kit as recommended above.
2) Calculate your pool volume. Lots of calculators online, or LxWxD.
3) Test your CYA. It is a harder test to do, but don't fret. Just keep adding water to each line and look for the dot. If you can see at 50 and can't see at 40, then your level is 50. Don't make it more complicated that that.
5) If your CYA is 60 or below, skip to #9
6) If your CYA is 70 or above, you will need to exchange water. a) use the PoolMath or online calculator here Online Pool Math. Enter your pool size, current CYA and a target of 40 or 50. I used 40 as my target because it is easier to add a bit of CYA, than to drain and refill more.
7) Once you know how much to replace and how big your pool is, read this: Drain/Refill. I used a sump pump with a valve on the outlet to match the amount of water added from my hose. Took me 2.5 days to replace 13,567 gallons in my 36K gallon pool. DRAIN AND REFILL NOW.
8) RECHECK YOUR CYA. If 60 or below, good to go!
9) Check your pH. If it is between 7.2 and 7.6, you are good to go. Go to #11.
10) If your pH is high, or low, use PoolMath or the calculator to get suggesting for adjusting. Adjust.
11) NOW you can check for FC. Use the FAS-DPD Chlorine test now from your kit.
112) Follow the SLAM process--> SLAM. Use this chart FC Level for SLAM with your NEW or Original 60 or below CYA number to get your target FC. Use PoolMath or the online calculator from above. Enter your current FC and your TARGET SLAM FC. It will tell you how much Chlorine to add. Add it! Check FC and Add often! Every 2 hours is best. Every hour is not necessary.
13) This is what I found works QUICK.
A) You must scrub EVERYTHING. OFTEN!!! Lights (remove them and scrub backside). Took me 4.5 days to SLAM because I didn't realize the inside of the tubes of the ladder might have algae. My OCLT was 2.5 for three days, no change. Took ladder out and cleaned it, BAM, OCLT < 1. Clean EVERYTHING and scrub the pool when you add Chlorine.
B) I tested FC EVERY 2 HOURS and added Chlorine EVERY 2 Hours during the day. You MUST keep the FC up to your target if you want the process to go fast. Take the weekend. Do it. It is worth it. If you go to work and let pool go 8-10 hours, SLAM will still work, it just might take a week or two.
C) Ignore everything else during SLAM. Do no other testing. Add nothing but Chlorine. NO POOL STORE, NO POOL STORE CHEMICALS. Nothing matters but the SLAM.
D) When and ONLY when you meet SLAM criteria. SLAM for one more day. Great insurance.
E) TRUST THE PROCESS DO NOTHING BUT SLAM.
14) After your SLAM, you can adjust everything else. The only other thing I had to adjust was my TA. It was about 140. I made an aerator EXACTLY like this: aerator pic. I put it on the sump pump I bought to drain the pool. I added muriatic acid to reduce pH to 7.0. Aerated for 12 hours. This would reduce TA by 10 points, and raised pH by .2 to 7.2. The muriatic acid reduces pH and TA. The Aerator increases pH without adding any chemicals. Took me ~3 days to get it to TA 70. pH increases the most at 7.0-7.2 because of outgas rate is higher at these values.

Now everything is great. I add chlorine and that's about it these days. I added borates (do a search), but is optional. I like the look and my pH is super stable.

It is simple, but takes work to get it done. Good luck!
Awesome, thank you so much! I appreciate all of the info and advice, especially the other devices in the pool like the ladder and light. Also good info about the borates, I've been reading about adding boron and debating this, I might try it after SLAM. Thanks again!

- Mike
 

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mdkraft99

Gold Supporter
Jul 19, 2021
13
Pinckney, MI
Pool Size
30000
Surface
Plaster
Chlorine
Liquid Chlorine
Ordered the Taylor K-2006C test kit, and in the meantime got some liquid chlorine to raise level, also downloaded the pool math app (awesome), and will get ready to test and then SLAM. In the meantime I'll keep brushing, keeping debris out of the pool, and backwashing. I can update once I complete the process. Thank you all again!

-Mike
 
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PoolStored

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Jun 24, 2021
2,777
Ashtabula, OH
Pool Size
30000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-60
You can stop backwashing too. Just note the pressure when you are done with backwashing the next time, then LEAVE IT ALONE, until the pressure rises 25%, then backwash.

If you do less (add chemicals, backwash etc.) and follow the simple process (chlorine, scrub), it will work just fine.
 

mdkraft99

Gold Supporter
Jul 19, 2021
13
Pinckney, MI
Pool Size
30000
Surface
Plaster
Chlorine
Liquid Chlorine
Hello everyone, my apologies for the delay, ran into a rough stretch at work and at home, and was out of town for a few days in between.

I did order the Taylor K2006-C testing kit and finally received that, and I got the TFP pool math app - LOVE it!! Tested the water and corrected a few times - getting the FC up to a higher level helped a great deal (followed the CYA-FC table on this forum). I realized through this that I was likely undershooting with the FC level all along. Brushed several more times as well, but haven't done SLAM yet because I knew I was in a stretch where I couldn't devote the time and attention needed.

The good news is that the algae is pretty much gone with the corrections I've made already and keeping FC up higher, combined with brushing. I still plan to SLAM, hopefully this weekend, but I didn't want to start when I knew I couldn't do it right - I'm hoping it will be a little shorter given the significant improvements I've seen already. I will say the water looks as good as it ever has, I'm so glad I came here to get advice and knowledge. I'm also confident that I'll have better management of the pool in the future as well.

Thanks again for all of the advice, I will update once done with the SLAM.

Cheers,

Mike
 
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mdkraft99

Gold Supporter
Jul 19, 2021
13
Pinckney, MI
Pool Size
30000
Surface
Plaster
Chlorine
Liquid Chlorine
Hello again everyone,

I finally finished the SLAM process, and the pool looks great! Took several days, but everything is done - CC = 0, overnight test with no loss, pool is clear, just waiting for FC to drift down to normal now.

Thanks again to everyone who gave advice, I'm so much happier now about maintaining the pool, and more knowledgeable and better equipped. And our pool looks better than ever (other than the debris in the pool from the storms last night)!

I'll be sure to monitor the forum and continue to post advice and questions.

Thanks again!

Mike
 

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Newdude

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18,178
NY
Sweet job MD !!

Now, we want to keep it like this. So that ‘minimum’ on the FC/CYA Chart is not just there as the lowest acceptable value.

You don’t want to approach it.
You don’t want to THINK about it.
You don’t want to DREAM about thinking about it.

336A7FEB-634C-4F35-94A4-16D792D40248.gif

Follow that mentality and all future discussions will be about the good deal you found on loungers, or other similar topics. :)
 
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mdkraft99

Gold Supporter
Jul 19, 2021
13
Pinckney, MI
Pool Size
30000
Surface
Plaster
Chlorine
Liquid Chlorine
Thanks again for the encouragement, I will be testing and following FC and other results more closely for sure, and definitely using the FC/CYA chart!

I hope I cam share some good deals on pool loungers soon. 😀

Cheers,

Mike
 
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PoolStored

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Jun 24, 2021
2,777
Ashtabula, OH
Pool Size
30000
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Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-60
Thanks again for the encouragement, I will be testing and following FC and other results more closely for sure, and definitely using the FC/CYA chart!

I hope I cam share some good deals on pool loungers soon. 😀

Cheers,

Mike
Any update on the pool lounger deals?
 
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mdkraft99

Gold Supporter
Jul 19, 2021
13
Pinckney, MI
Pool Size
30000
Surface
Plaster
Chlorine
Liquid Chlorine
Any update on the pool lounger deals?
Sorry, been a hectic month here....but sadly, no good pool lounger deals! But the pool chemistry has been the best it has since I've owned the pool! Thanks again to all who provided advice. Sadly pool season is ending here in Michigan, but I'm already excited for next season!

Cheers and have a safe and enjoyable fall and winter,

Mike
 

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