High CYA/CH

[Max Webster]

Reposting because I may have put this in the wrong forum originally:

I have a similar problem and seeking advice. I've stopped using pucks after learning about this site from a friend and having read enough to convince me the BBB method is the way to go. I have been fighting cloudy water and algae off and on for a while, and now beginning to understand why. I have an approx. 23k IG gunite pool. Initial readings from the Taylor K-2006 kit showed:

FC= 2.0
CC=0.5
CYA=100+
Cal Hardness=700
Ph=7.3
Tot Alk=250

Dilution was in order, so I drained roughly 2 feet of water out (it was painful to watch, and wasn't sure how far to go with it....). Next day results after refilling:

FC=0
CC=0
CYA=100+
Cal Hardness=575
Ph=7.3
Tot Alk=Not tested

Shocked per the Best Guess chart for the next 3 days.....I have not checked yet today but last night:

FC=7.0
CC=0.5
CYA=100+
CH=600
Ph=7.4
Tot Alk=170

I added bleach to bring the FC up to the 10.0 range. The water is not perfect, but better than it has looked in a while.....acceptable even, and no apparent algae.

I wish there was another way to lower the CYA and CH other than draining more water out. I have no plans to remodel the pool any time soon. I have not investigated the aeration of the pool water mentioned but will do so.

Should I just keep the FC level high due to the high CYA and follow the chart, or bite the bullet and drain yet again (and if so, how much?). I live in Texas, and the sun is plentiful and water from the sky is scarce lately (i.e. water bans will be in effect soon).

Thanks for any replies, and pleased to have learned about this site!

[hulla]

I'd try taking a gallon of pool water and diluting it with a gallon of fill water in a bucket. Then test the CYA level.

This should give you an idea of how much you need to drain.

[medvampire]

I think a drain and refill may still in order. You might want to take your pool water mix with distilled water half and half of each and test the dilution to see to see your level of CYA in the pool is at this time. This would give you an ideal your starting point to know the amount needed to drop that CYA level. I noticed your CH went up after refill so you may want to check your fill water for CH and ALK so you know what you are putting in to the pool. With that CH your ALK and pH needs to be a little low end to prevent calcium precipice and deposits.
Steve

[Gracy101]

I think a drain and refill may still in order. You might want to take your pool water mix with distilled water half and half of each and test the dilution to see to see your level of CYA in the pool is at this time. This would give you an ideal your starting point to know the amount needed to drop that CYA level. I noticed your CH went up after refill so you may want to check your fill water for CH and ALK so you know what you are putting in to the pool. With that CH your ALK and pH needs to be a little low end to prevent calcium precipice and deposits.
Steve

Geez - I'm lost....I get why he had/has to drain but I got lost when you and hulla started mixing water samples....Please explain in newbie terms

[chem geek]

Geez - I'm lost....I get why he had/has to drain but I got lost when you and hulla started mixing water samples....Please explain in newbie terms

The measurement test for CYA may max out at 100, so if you have more than 100 ppm CYA in your water the test will still show 100. That's what the "100+" means.

If you dilute your water by making a new mixture with half having your pool water (which has the 100+ ppm CYA) with half tap water (which has 0 ppm CYA) you end up with water that is a 50/50 mixture of the two so the amount of CYA in this mixture is the average between the "100+" unknown amount and 0.

So let's say you take this mixed (half diluted) sample to the pool store to be measured and now they say you have 70 ppm CYA. This means that your original undiluted pool water has double this amount, or 140 ppm CYA in it, because the average of 140 and 0 is 70 (that is, (140+0)/2 = 70).

Does that make sense?

Richard

[waterbear]

Reposting because I may have put this in the wrong forum originally:

I have a similar problem and seeking advice. I've stopped using pucks after learning about this site from a friend and having read enough to convince me the BBB method is the way to go. I have been fighting cloudy water and algae off and on for a while, and now beginning to understand why. I have an approx. 23k IG gunite pool. Initial readings from the Taylor K-2006 kit showed:

FC= 2.0
CC=0.5
CYA=100+
Cal Hardness=700
Ph=7.3
Tot Alk=250

Dilution was in order, so I drained roughly 2 feet of water out (it was painful to watch, and wasn't sure how far to go with it....). Next day results after refilling:

FC=0
CC=0
CYA=100+
Cal Hardness=575
Ph=7.3
Tot Alk=Not tested

Shocked per the Best Guess chart for the next 3 days.....I have not checked yet today but last night:

FC=7.0
CC=0.5
CYA=100+
CH=600
Ph=7.4
Tot Alk=170
I noticed your CH went up after shocking. Are you using Cal Hypo to shock? I would not use it since your CH is so high already but stick with sodium hypochlorite (bleach). Remember , shock is a verb (something you do to a pool to raise the FC level), not a noun (a specific product you add)!
I added bleach to bring the FC up to the 10.0 range. The water is not perfect, but better than it has looked in a while.....acceptable even, and no apparent algae.

I wish there was another way to lower the CYA and CH other than draining more water out. I have no plans to remodel the pool any time soon. I have not investigated the aeration of the pool water mentioned but will do so.

Should I just keep the FC level high due to the high CYA and follow the chart, or bite the bullet and drain yet again (and if so, how much?). I live in Texas, and the sun is plentiful and water from the sky is scarce lately (i.e. water bans will be in effect soon).

Thanks for any replies, and pleased to have learned about this site!

I would keep draining and refilling until your CYA levels get into range. Also you might want to test your fill water to determine how much calcium is in it. If it is very high then you might need to deal with thie calcium by using a sequesterant that has a high chelation ration for calcium (try googling 'calcium hardness reducer' if your pool store doesn't carry such a product. They are out there.)

[Gracy101]

Richard - can I sit next to you in class?