Pool green after multiple shock treatments, please help.

[Kirbyb]

Hello,

I am currently very frustrated with the pool. This is my second year owning a pool, and I am having some difficulty. I had gotten the pool almost clear, still cloudy, but almost clear. I had to leave town for a week. I added extra chlorine and kept the filter running. When I returned, the pool was green. I shocked it immediately when I got back, but that didn't help at all. I shocked one more time but still no change. I tested the water and the readings are

FC: 2.8
TC: 3.5
CC: 0.8
PH: 8.0
HARDNESS: 190
ALK: 80
CYA: 55
COPPER: 0.4
IRON: 0.3
PHOS: 188

At this point, I thought it may be copper. I adjusted pH and alkalinity then added metal sequestrant. The pool did not change in color after this. I tested the water again the next day. The readings are

FC: 0.3
TC: 0.6
CC: 0.3
PH: 8.2
HARDNESS: 176
ALK: 123
CYA: 48
COPPER: 0
IRON: 0.3
PHOS: 127

I fixed copper but pH stayed up. I added more pH decrease then shocked the pool in the evening. However, after all this there is still no change. Water is cloudy and green. The green color is uniform and I cant see any algae on sides or bottom when I brush. The water is only clear about a foot down though. I'm really not sure what to do at this point. I'd prefer not to empty the pool and refill, but I'll do anything at this point.




Pool is in ground, 33000 gallons sand filter with sand less than a year old. I'll add pictures as well. One before and one after.

 

[Texas Splash]

Hello and welcome to TFP! As we did before you, TFP can help. It did for us. First thing though …. the proper test kit. A TF-100 or Taylor K-2006C (link below). Anything less is not only taking chances with accuracy, but won't allow you to test at home frequently which is what's needed to clear a pool of algae. As for any residual copper, if there's some in there, only a water exchange can help lower that.

If we trusted those pool store tests, we might assume your CYA is around 50. So look at the [FC/CYA][/FC/CYA] and you'll see your FC should at "20" to effectively SLAM Process your pool to rid of the algae. It's a process that can take several days or longer, and you need one of those kits. So before we overwhelm you with any more info, I'd simply recommend getting one of those kits (I recommend the TF-100), read the SLAM link provided, and also save/read those Vital Links below in my signature. They will all come in handy.

Let all of that process for a minute and let us know what other questions you have.

 

[Neemer]

As a relative newcomer myself, I don’t feel qualified to offer a lot of technical advice yet, but I will say you have taken the first step to ridding yourself of bad information and excessive pool maintenance costs. Start reading the articles in pool school and try not to become overwhelmed with all of the information available. Be patient, follow the advice given, and you’ll eventually enjoy a sparkling clean pool.

Lesson #1: Shocking a pool is not an event, it is a process.

Best of luck!

 

[RobertScalchi]

FC: 0.3
TC: 0.6
CC: 0.3
PH: 8.2
HARDNESS: 176
ALK: 123
CYA: 48
COPPER: 0
IRON: 0.3
PHOS: 127

These numbers look like pool store numbers to me. Unreliable. Order the TF-100 or the K-2006 test kit. Read Pool School and understand what a shock or SLAM really is. If your cya levels are truly at 50. Shock SLAM at 20 ppm FC. Use Liquid pool chlorine or bleach only and not the chloromax type or the scented type or the splashless type just plain old regular bleach. Get your FC to 20 ppm and hold it there until water clears. Your pH is too high. For a SLAM to be effective, lower the water pH to 7.2 with muriatic acid. Your total alkalinity is on the high end of the range at 120 ppm but we can work with it, it may lower once you pour in the muriatic acid anyway. The total alkalinity or TA prevents wild fluctuations of pH swings when it is in range. Use the Pool Math calculator on this site to determine how much of what to add to balance your water out. Start with lowering the pH wait an hour, test the pH again, make sure it's 7.2, then add in your bleach to get you to FC 20. The reason why we are telling you to do it this way first is because anything over FC 10 PPM the pH is not going to yield a true test result over 10FC ppm. So set the pH first and then set the free chlorine. After that don't worry about the pH or anything else. Just stay focused on the SLAM and maintaining it, and running the filter until clear.

 

[Kirbyb]

Thanks for all of the advice. I do want to add that the testing is done using a TF100 test kit. Its not done by me, but the TF100 is what my pool store uses. I have one on order, but it's not in yet to test myself. Once it comes in I will be able to test periodically as I'm shocking that way I can get the FC to the appropriate levels. Not being able to test makes sense as to why I cant be effective against the algae. Being a newbie, I thought shocking meant just pouring in a couple gallons of chlorine for every 10k gallons. I will follow the SLAM method and test and update in a few days. Thanks again for the advice. I feel like I can start to make some progress now.