help adjusting

I have an inground, 21,000 vinyl liner with sand filter. water is clear but i'm having trouble getting the clorine to hold. i use a taylor 2006 kit, just got my new reageants in. my results are cya apparently is zero....the black dot does not disappear after using all the solution. Clorine 0, ph 7.0, TA 100 and calcium hardness is 40. I do drain my below below the skimmer in the winter, so i do have to add water, which i use my filtered well water to add. I have been adding bleach for the past week, keeping it high(not sure as to the number since i didnt have any reageants and was only using the oto kit from walmart that only checks clorine and ph) at the start it was slightly cloudy in the deep end. but now it is clear, just cannot get the clorine to hold. please advise

You need to get some stabilizer in there right away. We recommend 30-50 ppm. Your chlorine is being consumed by sunlight and whatever organics are in the water needing to be killed.

If you have access to a Sams Club, buy their 24lb pack of 1# bags of 100% dichlor shock. Each bag will add about 7 ppm of chlorine, and about 6 ppm of stabilizer, per 10K gallons of water. Otherwise, order dichlor from Amazon:

Kem-Tek Dichlor 22 lbs

We do NOT recommend buying dichlor locally, otherwise, at least until you are an EXPERT reader of chemical labels. The chlorinating pool chemicals sold at Walmart, Kmart, Costco, and most other local stores are diluted blends, sometimes with copper and other products with bad side-effects.

If you can't get dichlor easily, add enough 6% bleach to keep the FC at 3 ppm. You didn't report any CC so I'm assuming you don't have an active algae bloom. Buy CYA at the pool store (100% CYA) and add it via the sock method.

You also need to raise your pH to somewhere between 7.2 and 7.8. Since your TA is in a good place you'll want to use 20 Mule Team Borax which raises just pH and has very little effect on TA.

Now that you have the fresh reagents for your K2006 please post a full set of results tomorrow.

And, when you have a chance, please complete our new Pool Chart form -- it takes about 30 seconds, but will save much more than that.

Pool Chart Entry Form
Pool Chart Results

i am not close to a sams club but i do have a bioguard product called stabilzer 100 that i used before i found this forum. it is 100%cya. but i probably only have maybe 2 pounds. according to the label, adding 1 pound per 4,000 gallons will add 30 ppm of cya. do u think adding this much would be sufficient and get a reading before adding more? i have read on this forum to be careful about getting a high cya reading...and i dont trust myself in that i got a zero results. (but the dot never disappeared). it will be tomorrow evening before i can add this product. please advise as to whether i should proceed with this product and if 2 lbs is enough to start with. thank u for ur help!!!

In a 21000 gallon pool 2 lbs of stabilizer will only raise the level by about 10 or 11 ppm, not enough to show up on the test. I would start with 5 lbs initially which should raise the CYA by about 30 ppm if your pool is 21000 gallons. Even if you are not at 0 ppm now but it is too low to measure you CYA won't be too high if you are not using trichlor tabs but use bleach.

Add the CYA to the skimmer with the pump running and don't bother to test it for a week and don't backwash the filter for a week either. In the mean time keep adding bleach to maintain at least a 3 ppm FC level in the water.

A more important question is what is your combined chlorine reading after adding chlorine. I am assuming that when you say chlorine is 0 you mean FC. Telling us both FC and CC readings and how long after adding chlorine (and how much added) will tell us a lot about what is going on in your pool.

I don't use trichlor tabs, only beach. FC was at 0 yesterday...did not get a reading on CC.. as the sample never turned pink . i added 3 gallons of bleach yesterday and this morning at 9:30a my clorine reading with the oto was at 5, at 3p it was 2 and at 4:20p it was 0. i had to add more water this afternoon. the readings tonight at 8:15p using the taylor 2006 kit are FC 0, never turned pink, PH 7.8, TA 90, CYA...i still can see the dot at when all solution is poured into the cya cylinder. i have purchased cya now. i will add another 3 gallons of bleach now and will wait ur reply before adding the cya as i'm not sure whether to pour it in the skimmer or use the sock method and too please advise if i am still to add 5lbs or anything else i may need to do. thanks for all ur help!

5 lbs. of stabilizer will add about 30ppm of CYA. If you have already added 2 lbs. previously, then go ahead and add 5 more lbs. That should take you up to a reading of about 40-45 which would be a good level. You can add it either of the ways you mentioned. If you do put it in the skimmer, just keep your pump running 24/7 for the next 4 or 5 days and don't backwash the filter for about a week to be sure it has all dissolved. I add it different ways, different times. This year, I put it in the sock and put the sock in the skimmer basket and kept the pump running. The sock was empty within about 3 days.

if i put it in a sock and place in the skimmer, is it okay to add bleach to the skimmer? i add my bleach to the skimmer

the easiest way to add the cya is to pour it SLOWLY into the skimmer with the pump running. Run the pump continusously for the frist 24 to 48 hours, don't back wash for a week, and don't bother testing it for a week. You can add bleach to the skimmer after you add the cya with no problems.

If you do want to do the sock in the skimmer, just lift it out while you pour the bleach and then put it back in afterwards. Any of these ways to add the CYA is fine. I usually do add it into the skimmer. This is the first time I did the sock in the skimmer instead. Your choice.

i put 5 lbs of stablizer in on tuesday and also i put in 3 gallons of bleach because i had no clorine in the pool. i have not added anything else and the clorine is holding now. this mornings readings are
FC-10, CC-0, PH-7.4, TA-120.
I have not checked cya since adding the stablizer. Is FC at 10 okay? and other numbers okay?