Spa water quality issue.

[Guest]

I have been trying to get a community spa in shape and am having a bugger of a time. They were using trichlor tabs with a tab chlorinator. I want to drain it and start with fresh water, but the drain valve is broken and I can't get to my pool pump until this weekend and we need to keep it open short of having a community revolt. The CYA is way to high for an indoor spa so the drain will help that too.

Here are the current numbers after doing the following:
FC 24
CC 8
PH 6.8
TA 130
CYA 100

I added acid to bring the TA down to the 60-90 range (to keep foaming down) and it turned the water yellow. It was definitely a reaction, not the acid just moving through the water.

This drove the PH way down below 6.8. I added borax to bring up the PH. The TA dropped, but now has come back up to 130 since yesterday. I did NOT add Baking soda only Borax. I think the level of borates are holding the water at its current numbers keeping me from making big changes.

I had shocked it with bleach because of high CC originally. I am now using MPS shock since the health department is complaining about the FC levels and I am waiting for that to drop to reasonable levels. It is coming down, just slowly. The pool person had the chlorinator cranked up to full open on a spa with a POOL sized chlorinator.

I shocked with MPS again this am when I took that reading. I will be checking again shortly.

Short of draining it, how can I get the PH up to 7.5. The air jets have been running all day and don't seem to be helping the PH come up. I don't want to add borates since I am probably over the 50 ppm level now. No, I don't have the borate test strips.

I am going to test now and will post the results.

 

[Guest]

LOL! Helps if you read the test numbers right.

FC 13 (26 drops, duh!)
CC 3.5
PH 7.2 (aeration is working?)
TA 110
CYA way over 100, the level was halfway between the bottom and the 1st line on the tube of 100.
So I am assuming around 200-250. Gotta love the Trichlor tabs!!!

The shock levels at an assumed 200 CYA is 33, so I shocked with Chlorine to that level.

I guess the best I can do is shock to these levels until I can drain it.

 

[Guest]

This mornings results:

FC 18
CC 8
TC 26
PH 7.2

Added another 50 ounces of bleach to keep the shock level up.

Shouldn't the MPS get rid of the organics like the bleach, freeing up the chlorine in the CC compounds?

It seems like the MPS wasn't doing this.

 

[JasonLion]

Keep in mind that MPS will read as CC on the FAS-DPD test unless you have the special reagent to neutralize it.

 

[Guest]

Thanks! That explains the strange readings that did not seem to make sense. I will not be using the MPS again. No reason now with BBB.

As well, figuring out the correct volume of the spa. I estimated 900 gallon and it is really 500 gallon.

I got the valve to turn, the handle was stripped so while it turned the ball valve did not, by using the lockgrips. Drained and refilled. NO CYA and levels are all perfect.

This has been an adventure when you don't know volumes, or what has been added before or what all the unlabled and broken valves do!

 

[ChrisL]

I have found (and I believe some others might have too, if I remember correctly) that sometimes in my spa, an MPS shock can help clear cloudy water faster than chlorine alone. This may be particualrly true with a very high cya level as the cya will keep the chlorine from acting as quickly. Therefore, you may not want to stop the mps shocking completely. Just my experience.

Chris

 

[Guest]

Thanks Chris,

I just want to avoid the toxic soup created before. I will keep an eye on it and see how the bleach only goes.

I have the Ozone, MPS, Nature2 in my own spa and that is chlorine free so I know how clear the MPS can keep it. Then again, I know what has gone on in my spa and can predict how much of the MPS to use and when.

This community spa seems to get overloaded really easy, so trying to keep the chemicals to a minimum.