Thinking might have to drain part of my pool.

[Nilzlofgren]

Hello. I’m a 2nd year owner of a 20k gallon above ground pool. I’ve spent both seasons so far battling constant minor algae issues before I realized that I was under chlorinating my pool (simple math error on my part) but, now that I got that straightened out, I think my CYA is too high. I’ve been using the small chlorine tablets that are added everyday to the skimmer. Not sure wether it’s dichlor or trichlor, but it too has stabilizer in it. I’m using a Taylor K2006 FAS DPD test kit. My number for today,(07/15/19) were:
Water temp 87
Free chlorine- 4.5ppm
Combined chlorine- between .5 and 1 ppm
Ph-7
Total alkalinity 70 ppm
Calcium hardness- 75 ppm
Cya 70ppm
Not sure if CC could be .75, but at .5 the test tube stil had the slightest tinge of pink.
Thanks for all your help. John.

 

[duraleigh]

Welcome to the forum

Your CYA is a bit high for a manually chlorinated pool (no swg) but I would not be in a rush to bring it down. It deteriorates a little each month on it's own and I imagine you'll be around 50 ppm by the end of the swim season. Simply consult the FC/CYA chart in pool school to find our suggested range for A CYA of 70 and you'll be good to go.

How does your water look now?

 

[setsailsoon]

John,

Welcome and thanks for posting! Can you please add your pool info in the signature? It will help experts give you quicker advice. Just click on the screen name above right and click on "signature". Add your pool info there like size, type, equipment and model numbers. Then press save. After that this info will appear at the bottom of every post. Avoids you having to re-type it and often avoids a cycle of questions before experts can help. Also, just to clarify, what are you chlorinating with now?

Chris

 

[YippeeSkippy]

Just use liquid chlorine per the requirements for your higher CYA level instead of pucks. You may make it thru the rest of the season as long as you stay on top of your testing and daily dosing.
FC/CYA Levels

Maddie

 

[Nilzlofgren]

Welcome to the forum

Your CYA is a bit high for a manually chlorinated pool (no swg) but I would not be in a rush to bring it down. It deteriorates a little each month on it's own and I imagine you'll be around 50 ppm by the end of the swim season. Simply consult the FC/CYA chart in pool school to find our suggested range for A CYA of 70 and you'll be good to go.

How does your water look now?

My pool is always clear, but little algae spots always seem to pop up on the bottom. Tannish white in color. Looks like little grains of sand. They dissipate when you touch them.

 

[duraleigh]

That's almost surely dead algae which indicates you have live algae in your pool. You can try to get rid of it by elevating your chlorine up around 10 ppm for a few days and see if the "spots" go away. Brush them up into the pool water each time you see them.....gets it into your filter sooner and helps kill what is still living.