adjust cya before or after shocking

[BigDave]

10? What are you using to measure chlorine? What kit? How much dichlor did you put in? Do you know how many gallons your pool is?

[Kateyru]

I am using Leslie Basic Poolcare OTO test kit (made by Taylor). I misread, chlorine is 5 but that's the highest on the kit. I added 37 oz. of dichlor. Pool is about 22,000 gallons. thanks!

[BigDave]

According to The Pool Calculator 37oz of dichlor will add 7ppm of FC and 6.4ppm CYA to your 22,000 gallon pool and drop the pH by 0.27. You may be able to use this dose of dichlor 4 or 5 more times before reaching your CYA goal.

I think you're going to need unstabilized chlorine - Bleach (Liquid Chlorine) or Cal-hypo to clean up. The pool is consuming chlorine too fast to reach and maintain shock level with just dichlor.

You'll also need Borax to raise pH after dichlor lowers it. I don't know why you get such a strange reading but dichlor should push pH down.

You'll also need "The Good Test Kit" the Taylor K-2006 (or K-2006C) available from the link in Watermom's Sig. It will let you eaisly measure the high chlorine levels you'll need (from Ben's Best Guess Chart) to finish off the algae in yourn pool.

Go ahead and add one more dose of dichlor if that's all you have on hand but don't use more without getting a reliable reading on your pH.

[Watermom]

If your test kit only goes to 5 and is reading 5, then it could mean 5 or it could mean higher than 5. Same with your pH. It could mean 8.2 or it could mean higher than that. What color is the chlorine test showing? Dark yellow, orange, ?? I am not calibrated on dichlor dosages. What did the package say in regards to how much a dose of dichlor would add to your chlorine level? I will tell you that for every 10ppm of chlorine that it adds, it also adds 9ppm of CYA.

You really need to get a better test kit. An OTO/Phenol Red kit is fine for quick daily testing, but when you are trying to clear a pool, it isn't adequate. We recommend the Taylor K-2006 or 2006C (same kit, larger quantities). You can get it through the Amazon link in my signature below. Only order if the seller listed is Amato Industries as sometimes other sellers substitute the K-2005 instead which you don't want.

To get a more accurate pH reading, retest it when the chlorine is low. Repost with new numbers and order a good kit.

[Kateyru]

I just ordered K-2006 kit. An aside, Amazon vendor was VM Innovations so I went to Amato website to order. I forgot to mention that the PH level yesterday "scared me" so I added muriatic acid. This am the PH is 7.2 and chlorine is same 5, a dark yellow. Should I go ahead and add another 37 oz of dichlor now? I used Pool Calculator to determine amount, fyi. After that, should I wait to get better test kit before doing anything else? I really want to add borates (per sticky note) when I get algae straightened out.
Thank you, thank you, thank you for all your help!!!

[Kateyru]

PS, I just subscribed to the forum. Thanks for all the help!

[BigDave]

As you pH is 7.2, don't use any more dichlor until you can raise it with borax. I was under the impression that you had pretty much the same chlorine before and after adding the dichlor indicating a drop of 5 - 7 ppm. If your chlorine hasn't changed since yesterday, I'd wait to get accurate results with the K-2006. If you chlorine does drop to a level you can read with OTO, then I'd bring it back up to shock level with bleach.

BTW Thanks for subscribing!

[Kateyru]

So next step is to raise the pH with borax or should I wait on new test kit? If I raise the pH first, then I wait on new kit unless I can read chlorine level with current kit, right? then I would shock the pool? Will bleach be better to use than cal-hypo to shock? Should I leave filter running for now? Thanks!

[BigDave]

I wouldn't add another dose of dichlor with the pH at 7.2 as it could push your pH below 7.0. How low does your pH comparator read?

We're not sure how high your chlorine is, just that it's above 5ppm. You need to be at 15ppm for shock level - we'll be able to measure this directly when the K-2006 arrives. If your chlorine reading looks the same today as yesterday, then it's not being consumed fast and I'd be concerned with over-dosing until it can be reliably read.

When you can get a reliable (in range) chlorine reading, you can decide to: 1) Bring pH up with borax and dose with dichlor - or - 2) Dose with bleach or cal-hypo. I would avoid cal-hypo at this point as we have no CH reading (we will when the k-2006 arrives).