How are my numbers?

[SandyDittmer]

Hello,

I have an AG pool with deep end, 13,500 gallons, use bleach for sanitizer, borax and baking soda when necessary (none this year so far though).

Here are my numbers, and I just wanted to ask you experts if I need to raise my TA a bit or just leave it alone. Also...is my CYA in a good range if I like keeping the free chlorine level at around 3?

Water is crystal clear and about 73 degrees right now.

pH 7.5
TA 80
Fr Ch 4
Cmb Ch 0
CYA 32

Also...I am using test kit PS233. All the chemicals seem to be working fine, but I do notice that the R-0870 is a medium grey color. On my kit it says to replace it when it becomes this color. But I thought that is the color it was when I purchased it. What color should it be? Are there any other of the chemicals that need to be replaced periodically? I am on my third season with this kit. I'm not looking to spend more money, but do want things to work properly. If some things need to be replaced periodically, I would love to know which ones. I am very careful to keep everything dry. I store it indoors in a closet packed in the ziploc bag it came in.

Thanks,

Sandy Dittmer

[SandyDittmer]

Forgot to subscribe...

[aylad]

Hi Sandy, and welcome back!

I would leave your TA alone unless you having problems keeping your pH steady.....80 is just fine. At your CYA level of roughly 30, you're kind of on the edge of the envelope if you keep your FC at 3--I'd push it up a little higher to maybe 4 or 5 just to make sure you don't have problems. An alternative to that would be to maintain it at 3, but shock it on a regular basis.

As far as your DPD powder goes, it will change colors...it should have been white when you bought it, and the directions say that you should replace it when it's medium gray, but I have used the powder until it's dark gray (as long as it's not clumping) and it's been fine. If you're storing your kit in the ziploc bag away from heat, light, and humidity, then you can probably go 2-3 years with the reagents with no problem.

Janet

[chemicalbalance]

I think you are fine. If you use bleach, it will try to push your alkalinity up over time, so I wouldnt artificially increase the alkalinity with baking soda. Let it stay where its at.

As for the DPD powder, it does turn gray over time. Its fine. As long as it doesnt have any chunks in it, you should be all right.

You can buy DPD powder from taylor chemicals on line. It only costs a few bucks. www.taylortechnologies.com

[Poconos]

On the DPD powder issue, check this thread:
http://www.poolforum.com/pf2/showthread.php?t=4659

Al

[CarlD]

I think you are fine. If you use bleach, it will try to push your alkalinity up over time, so I wouldnt artificially increase the alkalinity with baking soda. Let it stay where its at.

You're kidding, right? Where did you EVER come up with this? There is nothing in Bleach that is related to Total Alkalinity. Bleach is basically Sodium Hypochlorite in a saline (Sodium Chloride) solution. It doesn't have the requisite Carbon atoms to affect Total Alkalinity.

Perhaps you have it confused with one of the other B's of B-B-B--Baking Soda, which WILL push T/A up.

You wouldn't happen to work for a pool store, would you?

[duraleigh]

Carld,

You are, of course, technically correct but I see no reason for the implied derision in your reply.

Checking chemicalbalance's other posts, he/she certainly seems to be genuinely interested in helping others and appears to have no agenda....... other than being perhaps a little new to using BBB.

[KurtV]

You're kidding, right? Where did you EVER come up with this? There is nothing in Bleach that is related to Total Alkalinity. Bleach is basically Sodium Hypochlorite in a saline (Sodium Chloride) solution. It doesn't have the requisite Carbon atoms to affect Total Alkalinity.

Perhaps you have it confused with one of the other B's of B-B-B--Baking Soda, which WILL push T/A up.

You wouldn't happen to work for a pool store, would you?

My guess is that chemical balance was thinking of pH. It's a common belief that bleach will raise pH and I think it actually will to a very small extent. Come to think of it, to the degree that it does raise pH, I think it would also raise TA a bit.

[CarlD]

My guess is that chemical balance was thinking of pH. It's a common belief that bleach will raise pH and I think it actually will to a very small extent. Come to think of it, to the degree that it does raise pH, I think it would also raise TA a bit.

Actually, not. Bleach IS alkaline, but the acidic reaction of chlorine in the water (ask Chem_Geek if you need an explanation) negates it almost perfectly. So bleach neither raises nor lowers your pH.

In that line, Di-Chlor is almost perfectly neutral in pH, but because of the chlorine acidic reaction, it lowers pH. Chlorine by gasification also makes the water VERY acidic.

[KurtV]

Actually, not. Bleach IS alkaline, but the acidic reaction of chlorine in the water (ask Chem_Geek if you need an explanation) negates it almost perfectly. So bleach neither raises nor lowers your pH...

I'm perfectly well aware of Richard's explanations of these processes. That's why I said that bleach will cause pH to rise "to a very small extent". After rereading Richard's explanation (see posts 9, 12, and 14 in particular), I'm still pretty sure that particular statement is accurate. The point of my post, however, was not to argue a fine point about pH and TA. I was simply trying to point out, in a non-confrontational way, what might have been the basis for chemicalbalance's statements.