Pool chemistry help beginner

[Jeff F]

Question coming from the new guy. I had a new 20,000 gallon plaster pool put in 7 months ago and the guy who did my startup seemed very knowledgeable and said just to keep the pool chemistry very simple, no scale removers, phosphate removers, etc, so that is what I've been doing. I read all the pool school info too, but could still use some help from the experts. I've been using the chlorine pucks, which was probably my first mistake. Now I am trying to make the switch to liquid chlorine. My CYA level really has gone up rapidly in the past few weeks. I believe this to be from the chlorine pucks I've been using. I have an inline feeder and I have been stocking it up with 4-5 tabs at a time to maintain a 3.5 ppm in my pool. My question is that I have been using 3 pints of liquid chlorine daily to maintain the same level now, but this doesn't seem very practical. I'm wondering if the chlorine should be able to last longer or does this have to do with my CYA level?

Also, my PH seems to stay in the proper range longer and does bounce around as much when my TA is 70-80 is this okay?

My chemistry is:

K-2005 Taylor

FC = 3.8
Ph = 7.6
TA = 80
CH = 220
CYA= 100

Thank you

 

[frustratedpoolmom]

Yes to the PH and TA.

I suggest you do an overnight FC loss test and see if something else is consuming your chlorine, 3 pints could be possible but perhaps something organic is consuming it.

 

[frustratedpoolmom]

Oh BTW I read again you said 3.5 ppm... but if you refer to the chart, your "MIN" free chlorine should be 7 with a CYA of 100. So if its been routinely below 7 then something is surely lurking beneath the surface.

 

[Jeff F]

I will do the overnight FC test and let u know. I'm blown away at how quickly the CYA climbed in such a short period of time. What do most people do that just use the chlorine tabs to keep the chlorine levels in check rather than liquid chlorine? Are they just keeping their chlorine levels super high. What would be my shock level right now for a CYA of 100?

 

[Isaac-1]

They don't their pools turn green they go to the pool store which sells them hundreds of dollars worth of magic potions, algaecides, phosphate remover, etc and if they are lucky it clears up for a few weeks, before coming back again then they are off to the pool store to spend more money, and eventually when the potions don't clear it up, the pool store says something about stale water, chlorine lock, etc. and tells them to dump and refill their pool.

 

[Jeff F]

Ok did the overnight FC Test and chlorine level went from 3.8 to 2.8 ppm? Should I be worried about this result? Water still looks crystal clear, but I'm concerned with my high CYA level still. I raised my FC to 7 this morning as well. We are in a drought in Calif. right now, so I don't want to have to drain and fill the pool too much? Any advice?

 

[frustratedpoolmom]

Ok. Its borderline. I'd say since it's clear, you may be ok. Now refer to the chart - your target is 12. Your "min" is 7. Don't let it fall below 7. When you use the PoolMath, your target is 12 when you calculate a dose.

Repeat the OCLT tonight to be sure. Keep it above 7 at all times to avoid a problem. What kind of filter is it? Will you be backwashing/vacuuming to waste? By lowering the water level a few inches at times - you will slowly drop the level without a major drain/refill.

 

[Jeff F]

Are there an issues that may come up with having my chlorine between 7 -12?

I have cartridge filters, would it benefit me at all to clean those?

I drained about 3 inches this morning and I' m refilling now. I guess I will do this a few times in the next couple weeks.

The problem that I think I'm going to run into is I go to work three days at a time and don't come home till the 4th day. That is what I was using the chlorine tabs for. Doesn't seem like I will be able to keep up On the liquid chlorine while I'm gone...

 

[Charlie_R]

You might be a good candidate for a SWG. Can be a bit pricey to get into, but will keep a steady supply of FC into your water.

If you do that, you won't need to drain and refill as much, just enough to bring the CYA to the recommended SWG level.

 

[frustratedpoolmom]

Yes clean the cartridges.

 

[Charlie_R]

You mention that you have the DPD K-2005 test kit. That isn't the FAS-DPD K-2006 kit. You can get the R-0870, R-0871, and R-0003 separately, all other components should be the same. If you need to SLAM your pool, you will need it. And if I'm not mistaken, the DPD kit is only supposed to measure up to 5, so you really do need the FAS-DPD just for day to day testing.

 

[Casey]

Ok did the overnight FC Test and chlorine level went from 3.8 to 2.8 ppm? Should I be worried about this result? Water still looks crystal clear, but I'm concerned with my high CYA level still. I raised my FC to 7 this morning as well. We are in a drought in Calif. right now, so I don't want to have to drain and fill the pool too much? Any advice?

If you lost 1ppm in an OCLT you are becoming very close to harboring organics and may need to SLAM your pool. With your CYA at 100ppm and running a 3.5ppm FC, the water could turn on you at any moment. If this were my pool and coming to the realization of a very hig CYA and low FC for an undetermined amount of time, coupled with losing 1ppm in an OCLT, I would SLAM it.

I also agree that you would do very well with a SWG since you are not home for 3-5 days at a time due to work and what not. It's not a free pass to not keep an eye on the pool but it is an excellent addition to your work schedule that can get you through without having the pool go monster green on you.