Chemistry Help

[Mitchum]

Hi,

I'm new to TFP and like what I've seen so far.

We bought a house two months ago with a pool. I've never owned a pool before so I headed to my local Leslie's store to figure out what I needed to do. Needless to say I bought all of the chemicals they suggested, including something to get my phosphates under control... Luckily, I stumbled across this site before I blew another $300 on chemicals I don't need.

I'm still waiting for my TF100 test kit to arrive, so I went to Leslie's again to have my water tested. Here's what I've got:

FAC: 5
pH: 8.0+
TA: 70
CYA: 60 - 70
TDS: 900 (I know, I know. Who cares!!)
Phosphates: 300 - 500 (ditto)

I currently use a floating Chlorinator (purchased ~$100 in 3" trichloro pucks :x ) and muriatic acid (which I have to add about once every two weeks) to keep things balanced. BTW, my pool was resurfaced about 6 months ago according to the seller. I also have been using the Phophate product they sold me. I don't plan to buy more, but I guess I'll use up what I have.

I plan to switch to a variable speed pump and SWG in the near future. In the mean time, other than adding some of the muriatic to bring the pH down, what should I be doing instead?

There is so much info floating around that I'm not sure if I should:

a) Donate my trichloro to the local hockey club and start using liquid bleach.
b) Keep adding muriatic acid to keep the pH down.
c) Add baking soda to bring the TA up (my buddy at Leslie's say's it's fine but the Pool Calculater says it should be 100 to 120+...)
d) Do something about my CYA level. I'd rather not remove/replace water if I don't have to. Will it come down on it's own when I stop using the trichloro?
e) Bite the bullet and Borate my pool? I have yet to see someone that is opposed to it...

Keep in mind that I plan to switch to a SWG in the next month or two.

Thanks!

 

[bobodaclown]

Hello,
Welcome to the forum. Sounds like you're learning. Pool school is a great place to start.
Boric acid is a little more expensive than using 20 mule team borax, but it's so much easier.

A. keep the trichloro, if you go away or if you need to bring the CYA up.
B. Muriatic acid is the best way to bring PH down.
C. Bringing up your TA may increase the speed of PH rise. Do you have any water features?
D. It will come down on it's own slowly due to splash out. It does also break down. Unless you have an indoor pool it's good to have some CYA in the pool. It becomes a problem when it's over 100 and you don't maintain enough FC.
E. Do you have pets that drink from the pool? If not I feel it's worth the extra protection. I've added it to my pool and have had no problems. I took the advice posted on this board and haven't had any issues.

 

[zea3]

Hi, welcome to TFP! You can manage with the CYA at 60-70 until you get the SWG up and running. You would need it about that level with a SWG anyway so just stay the course for now. According to The Pool Calculator, your FC target is 5-10 ppm. It is best to keep the FC at the upper end of the target range, since bather waste and other organic debris can cause the FC to drop by several ppm within a day. You never want to let the FC drop below the minimum of the target range.

I would stop using trichlor now and switch to liquid chlorine for your sanitizer. You can hang on to the pucks. As long as they are kept dry they will last for years. You can use them to boost your CYA when needed due to water replacement.

I would not make a big adjustment in TA yet, we don't have a CH test result and if the CH is high you will need the TA to stay low to avoid scale formation. Also if you decide to add borates you will be adjusting the TA during that process. The only down side to borates is you do not want pets or children to consume large amounts of borated water. If you see that being a potential problem then I would hold off on the borates.

Try and keep the pH around 7.2 and try not to let it go over 7.8. Otherwise, sounds like you are doing great!

 

[Mitchum]

Thanks for the quick feedback.

There is a spillway (3 foot drop) from the hot tub to the pool. I guess that this is aerating the pool causing the pH to rise a bit faster, yes? I guess when I get my VS pump, the aeration from this would be a bit less as the flow will be lower.

We do have three children (4, 6 and 9). I don't think they'll drink the water, but I can't be sure...

pH around 7.2? Everything else I see says to keep it between 7.5 and 7.8. Why 7.2?

Right now, I have a basic poolcare OTO Test Kit from Leslies. It only measures Total Chlorine and pH. I can only measure TC up to 5. I assume that the TF100 will allow me to measure FC at levels above 5, right?

 

[bobodaclown]

Yes, aerating the pool is causing the pH to rise a bit faster.
Read: pool-school/lowering%20total%20alkalinity
Not sure where you live, but why a VS and not a dual speed? The SWCG is a great call. Beats lugging jugs of bleach. (Did it for about 2 months and splashed 1 pair of jeans.) More stable chlorine level I feel.

Yes, TF100 will allow higher FC levels. Also FC + CC = TC Most test (cheaper pool store/wally world) only measure TC. One of the biggest gripes you'll run into is people not running there TC level of approx 10% of the CYA level. They'll say your TC is too high, they don't consider CYA. It can get you into trouble.

Don't make pool care difficult on yourself. I think the most important factor is keeping an adequate chlorine level in the pool so you don't run into trouble. Adjust the PH to range lower (maintain with MA 31.5%), knowing it will rise over time, then adjust CH and TA to keep the CSI a tad negative.

You track those parameters by testing. Daily at first, learn your pool, then every few days, then maybe weekly. TC/PH most important, TA/CH, CSI maybe monthly.

 

[Richard320]

Thanks for the quick feedback.

There is a spillway (3 foot drop) from the hot tub to the pool. I guess that this is aerating the pool causing the pH to rise a bit faster, yes? I guess when I get my VS pump, the aeration from this would be a bit less as the flow will be lower.

We do have three children (4, 6 and 9). I don't think they'll drink the water, but I can't be sure...

pH around 7.2? Everything else I see says to keep it between 7.5 and 7.8. Why 7.2?

Right now, I have a basic poolcare OTO Test Kit from Leslies. It only measures Total Chlorine and pH. I can only measure TC up to 5. I assume that the TF100 will allow me to measure FC at levels above 5, right?

Yes, a spa will aerate the pool a lot and cause pH to rise. I stuck an old paint can cap over the air intake for the spa returns, and moved the valve so the spa gets some circulation, but not 100%. That slowed down the pH rise. It also makes everything quieter.

I've managed just fine without borates for a couple years. I have high Calcium in my fill water, so I partially drain & refill whenever I get a chance. So I don't waste money on unnecessary chemicals that will just be getting pumped away.

I'd keep pH in the middle of the scale for now. Since I don't trust Leslies, I wouldn't do anything at all based on their tests. Wait until you get your own results, plug them into Pool Calculator, and see if you need to fiddle with pH. You probably won't. 7.4 is roughly the pH of human tears, so that's where I keep it when it's warm enough that people are swimming in it.

Finally, the TF100 will read FC up to 50 with the FAS-DPD test. Unless you need to shock, you'll never need to go that high!

 

[Butterfly]

Welcome to the forum

I'm still waiting for my TF100 test kit to arrive.....

You can email or call Dave and Meg for info on your kit. They have A-1 service! http://tftestkits.net/Contact-Us-5.html

 

[Mitchum]

You can email or call Dave and Meg for info on your kit. They have A-1 service! http://tftestkits.net/Contact-Us-5.html

A-1 Service indeed. I heard from Dave 2 minutes after my first post. I "thought" I was waiting for my test kit but it turns out that my wife forgot to order it. In truth, Dave was waiting for me... In any event, I've corrected my order problem and the check is in the proverbial mail.

Not sure where you live, but why a VS and not a dual speed?

I have three reasons, although I'm not sure how valid they are:

1. I live in San Diego and we're in the $0.30/kWh tier.
2. I plan to add solar and I'd like to be able to fine tune the pump speed for a) minimum speed for pool filtration, b) minimum speed to run the solar and c) minimum speed to operate the pool cleaner. It's possible that b and c will be the same speed and a two speed pump would work, but I'm not sure.
3. I bought into the hype that VS will save $$$... so that I can buy more chemicals at Leslie's...

This brings me to a another question that probably isn't in the right forum (Chemistry 201) but here goes:

I've been led down the Pentair path (SunTouch Controler, IntelliFlow VS pump, IntelliChlor SWG) by one of the Solar contractors that I met with. It makes sense that having all things from the same manufacturer should make integration easier. I've read that a lot and people seem to prefer the AutoPilot and/or CompuPool CPSC over the Pentair. If I do go with a non-Pentair SWG, any suggestions on a VS pump brand and a controller that will control the SWG, pump and solar controls?

 

[Mitchum]

I got my TF100 test kit over the weekend. I measured the water and this is what I got:

FC: 5
CC: 0.5 (this was actually probably 0. I've been reading a bit and the water was still very slightly pink in the FC test)
TC: 5.5
pH: 7.4
TA: 70
CH: 600 (water was purple, not blue so I need to re-run it by adding 5 drops first)
CYA: 60

Other than the CH result, I think things look pretty good. My pool was re-surfaced about 6 months ago (before we bought the house). Am I at the point where I need to do something about the CH if it's still high when I re-test? How high can CH be and still be okay?

 

[Richard320]

I got my TF100 test kit over the weekend. I measured the water and this is what I got:

FC: 5
CC: 0.5 (this was actually probably 0. I've been reading a bit and the water was still very slightly pink in the FC test)
TC: 5.5
pH: 7.4
TA: 70
CH: 600 (water was purple, not blue so I need to re-run it by adding 5 drops first)
CYA: 60

Other than the CH result, I think things look pretty good. My pool was re-surfaced about 6 months ago (before we bought the house). Am I at the point where I need to do something about the CH if it's still high when I re-test? How high can CH be and still be okay?

Play around with Pool Calculator and see what happens to the CSI. I'm at 725 again, hoping we get some rain to dilute things. I have gone over 1100 before, but that doesn't leave much wiggle room.

BTW, if you keep swirling, that purple may turn blue without adding any more. That's where a speedstir pays for itself. I hope you're using the 10ml sample where each drop counts as 25, or your wrist must be killing you.

 

[Mitchum]

My CSI is -0.31. So what you're saying is that CH by itself isn't a big issue. It's the impact of CH on the CSI that I need to monitor. Is this correct?

 

[Richard320]

My CSI is -0.31. So what you're saying is that CH by itself isn't a big issue. It's the impact of CH on the CSI that I need to monitor. Is this correct?

Yes. All other parameters being the same, see what happens when CH climbs to, say, 1000. You'll need to manipulate pH and TA to keep the CSI low enough that you don't start scaling. Temperature also affects the CSI. Actually, pretty much everything does. If you have high CH fill water, it is going to climb, and keep climbing. Which leaves you less and less room to adjust the other parameters and still keep the pool swimmable. And then you have no choice but water replacement or reverse osmosis, which is not widely available.