Does Raising CH Affect Other Water Levels?

[crokett]

Ok so just for full disclosure....

Test levels as of last night... ph 7.4, TA 110, FC of 5 with a SWG. Taylor K-2005 test kit.

Seasonal pool, ongoing issues as all y'all know with metals in the water. I can't keep the water color-free for more than a few days. Water turned the color of Mountain Dew Sunday. I started getting some iron stains on/around the skimmer and return. I converted to SWG last week and got some Purple Stuff yesterday. I doubled the dosage last night. The water is better, but is still a little yellow. However, the staining is clearing up.

I talked to the folks at Jack's Magic this morning. They were the first of 4 companies to suggest that it sounds like my issue is too low a CH level. They said any sequestrant but especially theirs works better at higher CH levels, like 200 or better. Mine is 90, or was the last time I had it tested a few seasons ago. I was told back then that it didn't matter much because a) it was a vinyl pool and b) it was a seasonal one. So I haven't worried about it till now. The Jack's Magic folks differed though. They said too low a CH can eventually degrade vinyl.

Pool Calculator says I need 109 oz of calcium chloride to raise the CH to 250, assuming an initial value of 90. I will test my water today to confirm the current level. So, if I add that much, will it mess up pH or TA? I am more worried about the TA. The pH I can adjust pretty easily. Do I add it all at once or over a few days?

 

[257WbyMag]

In a vinyl pool, low or non-existent CH is not a problem. High CH however, is problematic in all pools. Maybe somebody else can explain whether or not there is truth to the claim that Jack's Magic requires a baseline amount of CH in order to work effectively. I have not heard that before and with calcium being a metal, it seems to me that the presence of it in the water would only mean that more sequestrant would be required overall to accomplish the feat of sequestering the other metals that are present in the water.

 

[crokett]

I wondered about that too but he said Purple Stuff works better with more calcium in the water. At this point, I don't have much to lose, assuming adding the calcium doesn't screw up TA.

 

[JasonLion]

Adding calcium won't affect any of your other levels. I have never heard of sequestrant working better with calcium in the water, in fact I've heard the opposite.

 

[crokett]

I called Jack's back and talked to Jack himself. :-D. He is a nice guy. The information I've gotten from this forum and elsewhere says high CH makes sequestrants less effective, so I asked about that specifically. He said that at a CH of 450, he would agree with me. He said the added calcium makes it easier for The Purple Stuff to aggregate the metals into filterable particles that will either sink and can be vacuumed or filtered plus it will give the water a better 'feel'. His recommendation is to increase it up to about 200 so that is what I will do. Can I add it all at once, or should I do it over a few days? We are going out of town on Thursday.