Getting My Act together

Jrobertp

New member
Jun 21, 2016
3
Keller / TX
Go easy on me, I'm here to figure things out. This forum seems to be the best spot on the internet. (sorry for the long first post) I'm here because I have started getting algae growth on the walls of my pool.

This is my first pool, but so far I've had 3 very easy years of pool ownership. Really never a problem except replacing an old pump that died last year. For the last 3 years I've employed a pool company to maintain my water chemistry and my water has always stayed very clear. It has never bothered us swimming in it (I have 5 boys that swim almost daily may-september). I have done all the maintenance of equipment and cleaning myself. I choose a pool company to handle the pool chemicals on the recommendation of several others in my office who swear by them and also seeing that their yearly cost was less than my brother in law told me he spends on pool chemicals maintaining his pool himself. It seemed like a no brainer, and to be honest I've had 3 very happy, easy years with them.

However, for the last few weeks I've been getting some algae on the walls. This could definitely be contributed to by my lack of staying diligent with the cleaning maintenance. I really haven’t brushed my walls or cleaned the filter as often as I should, but I was having no problems. Now though with this new algae issue I'm brushing twice a week and the pool gets very cloudy from the algae (enough that I can't see the bottom of the pool through the cloudy water) A day or 2 later the filter will have cleaned the water back to clear, only for me to need to brush the algae off the walls again in less than a week. My past maintenance was less than recommended for sure, only backwashing about 4 times a year (but filter pressures were not rising quickly so I'd backwash when it rose around 8 psi.) I had only opened the DE filter once to rinse the grids by hand. This spring marks about 2 years since doing that, so I attributed my algae problem to that. So last Saturday (5/8) I brushed the algae walls again, let it filter for a few hours and then I opened it up, took the grids out and cleaned everything (it was very green inside). I got the filter back together, the pump running, added the DE, and then shocked the pool. (please forgive me, I did not test for chlorine levels because its almost impossible to do that with metro pool since they use chlorine gas and keep the levels VERY high) Then I ran the filter 24/7. I brushed the walls again the next day. By Monday after the pool company chemical man came in the morning the water looked crystal clear, however debris had settled to the bottom and the walls again looked to be getting green. Today I noticed that my filter pressures has risen about 8psi already, so I brushed the walls again, creating cloudy green / brown pool water again and backwashed the filter. There is less algae on the walls this morning than last Saturday, So it's possibly getting better, but I can't really follow a slam protocol with the current way my chemicals are managed. I'm wondering if I'm really getting algae due to my poor filter maintenance, or if I'm growing new algae because of the water chemistry. My best guess at this point is both are true...

I will be talking with the pool company about getting the algae problem fixed, but since I'm doing that I thought I would vet their plan for pool water chemicals here, and reconsider doing the chemicals myself. Today I took some of my water to a local pool supply store to get it tested. I know the results will bring lots of strong opinions here, and I’m happy to hear them, but I would love to understand the thoughts and reasons behind the opinions if you could help me out with that. I've gone ahead and read about the TFP plan for maintaining proper chemical levels and I'm definitely willing to conceded that the TFP way of maintaining water chemistry is technically sound, and practical. However, I do have 3 great years under my belt with this pool company, and also having several friends that absolutely swear by them doing the best job they've ever had with a pool company keeping their pool clear. Honestly, If I hadn't had this algae issue pop up, I'd probably never even give it another thought, because of the previous 3 years of clear water that has been wonderful to swim in.

As you look at these results, remember this company uses a "proprietary" plan for pool water and one of the main aspects of that plan is to use chlorine gas to achieve very high chlorine levels. I do not know their desired levels. Can you help me evaluate whats going on here?

Test Results:
Free Chlorine - 23.10
Total Chlorine - 23.10
Combined - 0.00
PH - 7.1
Alkalinity - 84
Adjusted Alkalinity - 30
Hardness - 219
CYA Acid - 161
Iron - 0.10
Copper - 0.00
 
Last edited:

mknauss

Mod Squad
TFP Expert
May 3, 2014
18,336
Laughlin, NV
Welcome to the forum!
IF those test results are close to correct, your CYA is three times what it should be.
For the CYA level you have, your FC is too low to eradicate algae.
Read SLAM Process and FC/CYA Chart
If you wish to take control of your pool water chemistry, and I suspect save a heck of a lot of money versus the nuke and run chemical company, you need your own test kit. See Test Kits Compared. I suggest the TF100 from TFTestkits.net. Get the XL version as you will need the extra reagents.
I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.
 

Flying Tivo

Well-known member
Jan 24, 2017
793
Monterrey, NL, Mexico
Just to peek your interest, I suggest you make a bet with your friends of at least 100 bucks, that they will get algae first than you if you follow TFP methods. This way, getting control of your pool back will earn you some bucks.

Just follow Martys advice and start reading, you got this!
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
10,295
Evans, Georgia
The use of chlorine gas is hardly unusual. Pool companies do this so that they don't have to come back to your pool before the free chlorine has totally disappeared.

Maddie :flower:
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
42,327
Tucson, AZ
There were companies here that also used chlorine gas. They intentionally raise the CYA very high (I think mine was pushing 250ppm) so that the chlorine they add should last until the next time they show up. Generally you have a roller coaster of FC where it is very high after their visit and then it is often too low to be sanitary by the next visit. Eventually they get behind and algae starts. Then their solution is to raise the FC extra high to try to kill it, but with the high CYA level it is often not enough. And do you get a refund for loss of use? Nope! Perfect business model.

They just hope to keep the water clear enough for the owner, even if the water is not safe, which it is not when the FC gets too low relative to the CYA.

So continuing the roller coaster or maintain better, safer, more consistent water on your own is your choice.
 

Jrobertp

New member
Jun 21, 2016
3
Keller / TX
Thanks for the thoughts. After some digging on the companies website I believe I've established some of their chemistry goals.

ph - 7.8-8.2. (mine is significantly below that)
Alkalinity 90 - 130
Chlorine 4.0+ ppm

They do not list any other goals in that section, But in another section they list that in their first visit they will bring CYA up to 100 ppm.

obviously my current readings are outside of those parameters.

I've done pretty much all the reading and study suggested here, it doesn't seem technically hard to take over the pool chemicals, but I'm not so sure it will save me a lot of money. Currently my cost is $600 a year for the pool chemical company. It seems, from what I've read here, I would be spending maybe $300 on the lowest end on chemicals to do it myself, but possibly a good bit more. It also looks like the plan is that I would test my water daily, and that's definitely not going to happen several weeks of the summer with my schedule. (travel etc.)

But I'm not willing to put up with algae, so I've got to get a fix one way or another.

Can anyone help me understand the safety concerns with pool water ie too much chlorine or too little? What are the parameters at which I should not let the kids swim?
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
42,327
Tucson, AZ
We say the pool is safe to use when you can clearly see the bottom and the FC is between the minimum and the SLAM level for your CYA.
If your CYA is really 160ppm, then to ensure that the pool is properly sanitized and that pathogen kill times are acceptable, the FC should always be above 12ppm. See the FC/CYA Chart (although I had to use PoolMath since your CYA is well outside out recommendations).
Below that there is a chance of person to person disease transmission and algae growth.
 

Fast7

Well-known member
Aug 8, 2018
72
Plainfield, IL
Think about pool as a pet. Would you want someone show up every two weeks or whatever schedule it is and dump all the food for your dog/cat into giant bowls and hope it will last till next visit?
Would rather feed it yourself everyday? Your pool will do much better if you "feed it" everyday. By maintaining constant chlorine level you will have a pool with the least harsh chlorine level, that's just high enough to sanitize it. Additionally, you wouldn't have to trust someone your pool is safe, you will KNOW it's safe.
 

Jrobertp

New member
Jun 21, 2016
3
Keller / TX
We say the pool is safe to use when you can clearly see the bottom and the FC is between the minimum and the SLAM level for your CYA.
If your CYA is really 160ppm, then to ensure that the pool is properly sanitized and that pathogen kill times are acceptable, the FC should always be above 12ppm. See the FC/CYA Chart (although I had to use PoolMath since your CYA is well outside out recommendations).
Below that there is a chance of person to person disease transmission and algae growth.
So based on what pool math is telling you my measurement of Free Chlorine at 23.1 should be high enough to Kill / prevent algae growth? Obviously its not enough to slam the pool which pool maths says would require a free chlorine amount of 63.

I'm just wondering since I do seem to have algae with my current water chemistry
 

Fast7

Well-known member
Aug 8, 2018
72
Plainfield, IL
Yes, according to PoolMath for such high CYA, daily maintenance FC should be around 17-19 and if it ever dipped bellow 12, that might allow algae to grow.
Once algae is visible, it would require FC of 63 to SLAM it.
It looks like it would be highly impractical if not downright impossible to clear algae without draining significant portion of your pool.
 

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