First time testing - check me please

[btozzo]

Hello All:

I thought I'd post a new thread for this one. It looks like my "Chlorine Lock" is over thanks to all of you. Also, following your advice I ordered and received my Taylor k-2006 test kit and love it. I'd like it if someone could do a little hand holding for me as I don;t want to screw up and I'm not exactly full of confidence yet. Here are my vitals according to my new kit:

1. Free Chlorine 1.6 ppm
2. Combined Chlorine 0.4 ppm
3. pH 7.4
4. Alkalinity 180
5. CYA < 30 ( I could see the black dot when it was completely full!)
6. Calcium Hardness 220
16 x 36 24000 vinyl in-ground with Hayward EC 65, 1 skimmer and 3 returns

My first questions is that I am backwashing and adding DE and my circulation is slowing down and pressure up to about 24 pretty quickly. When I backwash my pressure drops to around 12. Can this be due to my CYA? I seem to remember something about that in the Taylor book.

Second, I believe my CYA and my alkalinity are connected. How much of what should I add to get my CYA up a little?

Thanks everyone,

Bill

[sturev]

1. Free Chlorine 1.6 ppm
2. Combined Chlorine 0.4 ppm
3. pH 7.4
4. Alkalinity 180
5. CYA < 30 ( I could see the black dot when it was completely full!)
6. Calcium Hardness 220
16 x 36 24000 vinyl in-ground with Hayward EC 65, 1 skimmer and 3 returns

My first questions is that I am backwashing and adding DE and my circulation is slowing down and pressure up to about 24 pretty quickly. When I backwash my pressure drops to around 12. Can this be due to my CYA? I seem to remember something about that in the Taylor book.

Second, I believe my CYA and my alkalinity are connected. How much of what should I add to get my CYA up a little?

In your last thread you mentioned having a bunch of "rap" at the bottom of your pool; are you still cleaning that up/perhaps that's affecting your filter pressure? With your level, CYA would have nothing to do with it (I don't think it would at any reasonable level).

CYA and TA aren't connected, it's pH & TA that are. If you up your CYA between 30 & 50 you'll see less chlorine loss everyday. Some people keep it higher due to sun/heat, but then you have to keep your chlorine levels up (see the Best Guess CYA chart). Be careful adding CYA, it takes a few days/week to show up on a test after adding it.

[waterbear]

Hello All:

I thought I'd post a new thread for this one. It looks like my "Chlorine Lock" is over thanks to all of you. Also, following your advice I ordered and received my Taylor k-2006 test kit and love it. I'd like it if someone could do a little hand holding for me as I don;t want to screw up and I'm not exactly full of confidence yet. Here are my vitals according to my new kit:

1. Free Chlorine 1.6 ppm
2. Combined Chlorine 0.4 ppm
Use the 10 ml size sample instead of the 25 ml size. A test resolution of .5 ppm is more than enough and you will save on reagents!
3. pH 7.4
4. Alkalinity 180
5. CYA < 30 ( I could see the black dot when it was completely full!)
6. Calcium Hardness 220
16 x 36 24000 vinyl in-ground with Hayward EC 65, 1 skimmer and 3 returns

My first questions is that I am backwashing and adding DE and my circulation is slowing down and pressure up to about 24 pretty quickly. When I backwash my pressure drops to around 12. Can this be due to my CYA?
No, nothing to do with CYA directly but if you have low CYA and a lot of sun you might be dealing with nascent algae blooms. How much DE are you putting in when you recharge after backwashing and how much DE does your filter take? (I am not a big fan of backwashing DE filters but feel they should be broken down and then recharged when they need cleaning. You never really know how much DE you are backwashing out and it is very possible to over or undercharge them after a backwash.) Is your water cloudy or clear? If you have cloudy water then it just means the filter is doing what it is supposed to anc filtering out stuff
I seem to remember something about that in the Taylor book.
reread the book
Second, I believe my CYA and my alkalinity are connected. How much of what should I add to get my CYA up a little?
CYA does add to total alkalinity but not to the buffering effects of the bicarbonate in the water. Taylor says that the contribution by CYA should be ignored and give a formula for corrected TA. However, the contribution to TA by CYA is about 1/3 the CYA reading at a pH above about 7.4 and and about 1/4 the CYA reading below that so, unless you CYA is extremely high (say in the neighborhood of 100 ppm) it really is not going to make any appreciable difference and can be ignored. In your case, with a CYA of less than 30 ppm the difference between uncorrected and corrected TA readings is smaller than the precision the TA test is capable of!
Thanks everyone,

Bill

To raise your CYA you add CYA (cyanuric acid, commmonly called stabilizer or conditioner at the pool store). In a 24000 gal pool every pound (16 oz by weight) of CYA will raise the level by about 5 ppm. I would pour 2 lbs. SLOWLY into your skimmer with the pump running, run the pump 24 hours then switch back to your normal run time, do not clean the filter for a week and then retest the CYA. Repeat as needed to get into the 30-50 ppm range.

[sturev]

CYA and TA aren't connected, it's pH & TA that are.

Thanks Waterbear, I didn't know that about CYA and TA...

[waterbear]

Thanks Waterbear, I didn't know that about CYA and TA...

It really only become an issue with the use of very acidic trichlor where higher TA is needed to keep the pH from crashing dangerously low. With Bleach and other unstabilized forms of chlorine lower TA will actually contribute to better pH stability and slower pH rise. (It is very rare for a pool on bleach, cal hypo, lithium hypo,or a SWG to need borax or soda ash to raise the pH...unless there is something added that drops the pH like too much acid or an overdose of metal sequesterant. The trend is for such pools is for the pH to rise as carbon dioxide outgasses and adding acid is the norm. When a pool is on trichlor and the CYA is very high (Imagine that!) THEN adjusting TA for the CYA becomes more important and it is not usual to have to add acid to such pools unless dosing errors are made with the soda ash.

[waterbear]

Bill,
Just a hint with the chlorine test. Use the 10 ml sample instead of the 25 ml. The resolution is .5 instead of .2 which is usually good enough and you don''t use as much of the R-0871 reagent.
Al

Already suggested that in my first post.

[Poconos]

Sorry Evan. Missed your comment. Deleted post.
Al

[CarlD]

Already suggested that in my first post.

Consider it the strength of re-iteration!

[btozzo]

Thanks everyone. Alright, so I think I'll take apart my filter and clean it for the 5th time this season! Then once that's done I'll add the CYA as you guys instructed. I can't have the circulation stop every night so I really want to take care of that first. I'll also keep vacuuming the hell out of it. If this doesn't make sense let me know. Thanks again everyone!

Bill

[waterbear]

Thanks everyone. Alright, so I think I'll take apart my filter and clean it for the 5th time this season! Then once that's done I'll add the CYA as you guys instructed. I can't have the circulation stop every night so I really want to take care of that first. I'll also keep vacuuming the hell out of it. If this doesn't make sense let me know. Thanks again everyone!

Bill

If your DE filter is rising in pressure fast then the grids might be fouled and in need of soaking in a good degreaser like TSP or automatic dishwasher detergent.