# Thread: How much does granular stabilizer raise CYA? Im at 100+

1. ## How much does granular stabilizer raise CYA? Im at 100+

Hi, My name is Kevin and I have been pool stored.

Before finding this site, just recently, I was told my CYA was too low (@ 30). The kid at the pool store told me to put in an entire 4lb bag of Suncoast Stabilizer into the skimmer. I did and now the CYA maxes out on the test kit at 100+. I have noticed that my SWCG cannot keep up anymore at its normal setting and have since raised it to keep FC maxed out at 5+ on my cheapo kit. My Taylor kit is ordered.

My question is to all the math wizards out there. If I was at 30 before, and added a 4lb bag. What number should I be at now. If just above 100, ok. If 200, should I drain and start over?

Any help is mucho appreciated. Oh yeah, Have had battled black algae in the past in this pool and am afraid to let the FC get below 3. Ever.

Kevin

Today's #'s
FC: 5+
PH: 7.8 (added 2.5 cups MA)
TA: 100
CYA: 100+
Salt: 3100

2. ## Re: How much does granular stabilizer raise CYA? Im at 100+

The 4 lbs. should have added roughly 40 ppm of stabilizer and put you around 70 if your pool volume is correct. You can check it yourself using the pool calculator. Welcome!

3. ## Re: How much does granular stabilizer raise CYA? Im at 100+

You don't need to be a math wizard, Pool Calculator will do the number crunching. Bookmark that page - it's priceless!

If, indeed, your pool is 12000 gallons, 4 lb (64 oz) stabilizer will raise CYA 40 and lower pH by .74.

Soooo.. pool is smaller than 12000 gallons, initial reading was wrong, or current reading was wrong. Or the bag was bigger than 4 pounds.

My advice is to recheck the pool volume calculation. If it's right, then add liquid chlorine to get FC up to about 10 and keep it there until your Taylor kit arrives. Pool calculator will tell you how much to add. You can measure 10 with the color block by diluting your sample 50/50 with distilled water. If you have a fancy water filter on the kitchen sink or refrigerator, that should have no chlorine, either. Measure the 50/50 sample and double it. As a double check, you can also try a 1:3 dilution and triple it.

Once you get the kit, carefully do the CYA test. If it's still over 100, dilute 50/50 and try again. Once you have a fairly accurate reading, you'll know how much to drain, if any.

As an aside, if the SWG can't keep up, you may have an algae bloom starting, in which case you definitely need to get some liquid chlorine in there to keep it at bay until your FAS-DPD kit arrives and you can shock it scientifically.

4. ## Re: How much does granular stabilizer raise CYA? Im at 100+

Thanks for the advice. What is the most accurate way for determining pool gallons. I have a rectangular pool, but it has a large semi-circular sun shelf (coming out 7' in each direction from one corner) in the 6' deep end. Any way to determine how much water is offset by the sun shelf? To then be subtracted from the gallons determined by the formulas I have seen for rectangular pools?

5. ## Re: How much does granular stabilizer raise CYA? Im at 100+

How deep is this shelf? The area of a quarter circle is easy, but to get volume, we need the third dimension.

6. ## Re: How much does granular stabilizer raise CYA? Im at 100+

Picture a corner in the deep end of a rectangular pool, come 7 feet out from the corner in each direction and make a radius to connect them. It is 6' deep at that end and the shelf comes within 2" of the surface. So its approximately 5'10" deep.

7. ## Re: How much does granular stabilizer raise CYA? Im at 100+

Originally Posted by nolefan
Picture a corner in the deep end of a rectangular pool, come 7 feet out from the corner in each direction and make a radius to connect them. It is 6' deep at that end and the shelf comes within 2" of the surface. So its approximately 5'10" deep.

8. ## Re: How much does granular stabilizer raise CYA? Im at 100+

Ok, then if my math is right:

Rectangular pool: Length x witdh x avg depth x 7.48
(L)23.5
(W) 17.5
(Shallow end) 3' (Deep End) 6' = (Avg Depth) 4.5'

23.5 x 17.5 x 4.5 x 7.48 = 13,842 Gallons

13,842 - 1,600 = 12,242 Gallons

So I wasn't too far off, Pool store calculations must have been off when he tested. At least I figure i'm closer to 100 than 200. That makes me feel better. I really appreciate the help. Let you know the chlorine numbers by the dilution test tonight.

Kevin

9. ## Re: How much does granular stabilizer raise CYA? Im at 100+

Hi Kevin and welcome to TFP

You can also do a chemical measurement to help confirm pool size.

A gallon of 6% bleach should raise your FC 5PPM (assumming 12,200 gallons).

It the 5FC PPM is incorrect, you can back into the gallons.

You'll need the FAS/DPD test for this.

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