New to TFP, and looking for ideas on managing high CYA

[arjaygee]

I've been a pool owner for 8 years now, and have been doing self-maintenance for 7.9 years (only took a few weeks of having a pool guy before realizing I needed to do this myself). I discovered this gem of a website a few weeks ago -- not sure how this site managed to escape me for so long but just happy to be on-board now.

Anyway, enough on the life story intro, on to my question. Shortly after reading this forum, I purchased a Taylor K-2006 test kit to understand the real chemistry of my water, and here are the results:
FC: 3.0 ppm
CC: 0 ppm
PH: 7.6
TA: 130 ppm
CH: 1050 ppm
CYA: >100 ppm

I think it's obvious which chlorination method I've been using from the numbers above... yep, Trichlor pucks. So, what to do next. From reading various postings, I've concluded that I must get CH and CYA levels down ASAP, and the most direct way to do this is to purge and replace my water. So, what are all of the practical options? I could do a complete drain and replace but I was thinking about maybe draining 1/3 to 1/2. The other thing is that my plaster does have stains, and it seems like the time to address this, if I'm already thinking about draining the pool. I'd rather not do a full blown acid wash, so what if I drop PH on the partially filled water and spot treat the plaster exposed from partial draining? Just throwing a few thoughts out there but I'd like to get your collective opinions and ideas.

Thanks in advance...

 

[JasonLion]

Welcome to TFP!

Your two options are to replace water or to get an RO treatment. RO (reverse osmosis) isn't available everywhere yet.

You have a lot more control when doing an acid wash if you do a complete drain. Your plan to do a partial drain and lower the PH in the remaining water could work, but it runs a lot of risks. You won't have much control over what happens, especially since you can't run the pump with the water level way down.

 

[arjaygee]

So, yesterday I drained ~60% of my water, and now I'm in the refill process. I decided to hold off for a few seasons before doing the acid wash -- too much going on in my life right now to deal with that. Here's a list of what I think my steps are at this point, and I just wanted to get a confirmation or possible corrections:
1. While waiting for the pool to fill up, stock up on liquid chlorine
2. Make sure I've got plenty of acid (I have 4 1-gallon jugs)
3. Once I have enough water, start the pump (I think I read somewhere that I should divert to 100% main drain?)
4. Add chlorine??? -- here's where I'm not sure of the order (i.e. get the pump going and measure or get a dose of chlorine in?)
5. After a few hours of running the pump, use my Taylor test kit to take measurements and plug data into the pool calculator to determine what quantities of what of the 3 B's need to be added.
6. Priority is to make sure I get the right dose of chlorine in, and slowly work my way up with other things (read something like this in one of the forums).

For chlorine, do I just follow the calculated dose or something higher?

Thanks.

 

[JasonLion]

There is no need to add chlorine as the very first thing, that can easily wait an hour. Otherwise that all sounds good.

 

[gordyjamz]

Wow that calcium reading is pretty high! Did you do a test on your fill water for hardness level? That could be the source for the calcium. A lot of municipalities, as a cost saving measure, are cutting back on the water softening during water treatment. Just an FYI.

 

[257WbyMag]

Wow that calcium reading is pretty high! Did you do a test on your fill water for hardness level? That could be the source for the calcium. A lot of municipalities, as a cost saving measure, are cutting back on the water softening during water treatment. Just an FYI.

Very true and a good point to mention. Such is often the case in the desert southwest especially.

 

[keywest5]

Rick,
Good you are waiting on the acid wash...I did mine a few times over the years and it made the plaster rougher each time.
More places for algae to hide. Sometimes a little stain just ain't so bad.
Wishing you well, God Bless,
Paul

 

[Richard320]

Been there.

I started doing my own maintenance with CYA 220-240, CH above 500. But water restrictions precluded draining it last year. So... I kept FC way up there. Had to really watch pH and TA. My CH peaked at 1100 once.

Through obsessive testing and careful balancing, along with a lot of partial drains to water the lawn then refill and finally lots of rainwater dilution, I now have CYA down to 40. CH is still high.

I never had an algae bloom all year. It can be done. And in fact, the blotchy Calcium scale is slowly lifting. Lots of brushing with a steel brush and keeping CSI negative did that.

Re-read the how-to on lowering TA, you'll almost certainly be needing that. There have been some good threads with ideas and pictures for homemade aerators.

I also recommend ordering up a speedstir. It really makes the CH test easier.

 

[chem geek]

There are also other, more expensive, ways of maintaining high CYA pools that involve use of algaecides to prevent algae growth and clarifiers to help clear the pool since the lower active chlorine won't oxidize as quickly. If you were to go this route, the only product I'd recommend would be PolyQuat 60 added weekly. It is an algaecide and a mild clarifier and has no significant side effects (it somewhat increases chlorine demand). However, just keeping the FC up higher as Richard did is the least expensive and most straightforward approach. Note that the PolyQuat will still require chlorine in the pool, but it will help to prevent algae from growing at lower FC levels (FC/CYA ratios, technically).

 

[arjaygee]

As always with this site, great input from everyone -- thanks for all the ideas.

Here are my current readings (1 week after refill):
FC: 3.6
CC: 0
PH: 7.6
TA: 130
CH: 800
CYA: 90

Also, fill-line CH measured at 225.

So, I didn't quite make as big a dent in pulling down TA, CH, and CYA as I had hoped but I'm heading in the right direction. I was very pleased with how quickly I was able to get FC and PH to pop into the sweet spot, and the water looks great. Can't say enough about the Pool Calculator on this site!!!

I just ordered the Pool Pilot Digital SWG system, and am thinking about doing another partial drain (maybe 30% this time?). TA didn't even budge, so I'll read up on what to do there. I do have a wall-mount water feature, so I'll start by enabling that for aeration. By the way, my wife thinks I've gone completely nuts but what's new...

Thanks again. Hope someday soon, I'll be able to go from "Grasshopper" to "Master".