Greetings from Indiana!

HeatherEG

Member
Sep 10, 2021
11
Indiana
Pool Size
15000
Surface
Fiberglass
Chlorine
Liquid Chlorine
We have a 15,000 gallon fiberglass pool that I've been taking care of for eight years the way the previous owner taught me. Well, it turns out she was mistaken about a few things and now I've got a situation on my hands. I've just ordered the K-2006C test kit but it won't get here for a week or so. Until then I've got to wing it with the kit I have. I know this is just a first greeting. but I wanted to let you know what I'm starting with. I'll find the right forum to post in to get help.

Everything looked great all summer until I swapped out filter cartridges and then the pool got hazy. After a week, I re-swapped the filters and they were covered with a brownish slime. I cleaned them off and put them to soak in water with a fair dose of chlorine while I used the other pair. The haze kept getting worse. I took a water sample to the pool supply store and my calcium was a little high and my phosphates were off the charts high. I've been told before and was told again, to do a partial water change. I've been afraid to drain water out of the pool for fear of damage to the pool (not popping out of the ground as we are on a hill well above the water table), but this time I did it. We took out and replaced over a third of the water. While the water was low, I checked the pool light well and found a light brown, bubbly slime. I sprayed it all with pool chlorine but without the pump running, I couldn't vacuum so didn't clean it out yet. So I have some sort of algae but I can't identify it from internet photos and the pool store guy didn't have a clue.

Here are my readings from the pool store computer. They mostly agree with my basic test kit except I show my alkalinity at 210.
Total dissolved solids 3500
pH 7.5
Total Alkalinity 145
Calcium Hardness 300
Optimizer 25
Free Chlorine 0.7
Total Chlorine 3.2
CYA 150
Phosphate 3847

That's where I am. I've started using liquid pool chlorine. Anyway, thanks to this site, I've learned a little over the years and hope now to learn a lot more.
 
Welcome to the forum!
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.
 
Hey Heather and Welcome !!! Not much we can do until the kit comes so add the 5ppm daily like Marty suggested above.

If the CYA is right, and lucky for you the pool store gets this one wrong alot, you’re going to need to drain at least 2/3 of the pool. Tabs and Granular shock raise the CYA to unmanageable levels and the pool stores love to sell/use both.

Hang tight until we get good test data and can hatch a plan. There’s oodles of great folks here always happy to help a fellow pool enthusiast.
 
No worries. We'll get you all fixed up. Welcome! :wave:

full
 
I love the photo! I rarely go to the pool store although we have two and one is locally owned and run by one person who has been more knowledgeable and helpful. Unfortunately she doesn't have a computer to do a full water analysis. I mostly went by what the previous homeowner taught me and that was tabs and powdered shock, along with scum preventer and scale preventer.

How do I know what 5ppm of chlorine is? One gallon? I can measure total chlorine on my current test kit but to be honest, the color scale for chlorine is all so similar, and the color of the liquid gets darker the longer I take to read it, so I never know exactly how much I've got. I can ballpark it to know if I'm in range and that's what I've done. I'm still running the tablets. I figure the CYA is already so high another few weeks to finish the year aren't going to make much difference, so the pool has enough chlorine from those but I'm still adding a gallon of liquid pool chlorine each evening for now. If I get it up to 5ppm, would that be too high to swim in? The pump/filters run 24/7. I have no bypass for the filters so can't ever vacuum to waste and it can't be back-flushed, in case that comes up. The pool is circa 1996 or 97.

Oh, and we have a powered cover which is dark, opaque and always on the pool when we're not in it or messing with it, so I don't lose much chlorine to the sun. I should have mentioned that. I also like the pool on the warm side and the cover heats it up most of the summer since it's so dark. This time of year I have to use the heater a little too. I know algae likes warmth so I let it be cold for a couple of days after the refill, and after I had sprayed the light well with chlorine. I hope that stopped the growth.

With it being fiberglass, I can't safely drain 2/3 of the pool all at once. We just did over a third and I don't think my husband would be thrilled if I were to want to do it again yet this year. We usually close it in October, so I'm just trying to get it clear, clean, and reasonably balanced (pH, and alkalinity at least) before we do. I know taking out a third of the water at a time will have diminishing returns. I saw that you can do a simultaneous fill and empty by using a formula to figure out which hose to put in the deep end and which in the shallow. But even that will have to wait until next year, I'm afraid. Still, that might be a way for me to get rid of more CYA. I read about the tarp method and thought that was very clever but I don't know if I'm brave enough to try that.

I'm going to clean out the light well today so the algae will be physically removed. I don't have any in the skimmer and there are no other nooks and crannies in our pool for it to hide in. I'll swap and clean filters again after that's done.


Thank you all here for your help. I know I will be needing it a lot in the spring when I'll be able to tackle the CYA problem a little better.
 
How do I know what 5ppm of chlorine is?
Download the poolmath app and setup up your gallons and pool type. Then it lists all chemistry parameters. For FC for example, click on FC. It will open the page to enter the type of chlorine along with the %. Enter where it is and where you want to be (or in this case, use 0 and 5) and it will tell you you need XXX ounces of bleach. Or 1 gallon 2 quarts. Or whatevs.
If I get it up to 5ppm, would that be too high to swim in?
No. Certainly not with the CYA so high.
Thank you all here for your help. I know I will be needing it a lot in the spring when I'll be able to tackle the CYA problem a little better
We will be here to assist :)
 
96 ounces of 10% liquid chlorine will give you 5ppm of FC. :)

If you're on a computer/laptop....go to the bottom of this page and see the PoolMath I find this version of pool math easy to use when I want to compare chemical additions and how they'll affect things.

Maddie :flower:
 
Thank you! I did download PoolMath onto my phone, so I'm ready there, and the new testing kit should come today, so I'll have some good numbers to plug into it soon. It occurred to me that I should just use my current test kit to check total chlorine ppm but it only goes up to 3 and I'm there, maybe over. Someone mentioned leaving my pool light out so the well gets chlorinated. I can't leave it hanging by it's cord in the pool, or up on the deck because of the automatic cover, but since it doesn't screw into the wall (the part of the bezel it screws into broke off long ago) I just tip it out a little and use a squirt bottle full of chlorine to shoot a bit right into the well and put the light back. So it should be getting plenty of chlorine. No regrowth that I can see.