questions about aerating

[camueller]

Hello all. My TA is high (175) and I would like to add borates. I know I need to lower the pH with MA and aerate to bring the pH back up, and repeat until the TA falls to where I want it. I lowered my pH a little to 7.4 and thought I'd bring it up to 7.8 or so before knocking it back down. We want to swim tomorrow, so I don't want to stray too far from norm.

I have a submersible pump I got from Home Depot that has a 1 1/4 threaded output. I rigged up a piece of 1 1/4 inch pvc so that I could sit the pump on the pool floor in the shallow end, and the PVC pipe sits about 3 inches above the water line, and shoots water out the top.

But I can't get the pH to rise. It's been running for a couple of hours, and I haven't seen it budge from 7.4. I'm tempted to let it aerate overnight, but slightly afraid it may be way too high if I do that when I wake up. What's going on here? Am I just not waiting long enough? Is my aeration method not working?

 

[pooldv]

That is a little odd. It won't hurt for PH to be high overnight, you can lower it in the morning. Also, lowering it to 7.2 instead of 7.4 will speed the process.

 

[camueller]

Cool. Thanks for the info. I was just re-reading the aeration thread in pool school and on one of the links to a DIY aerators, the poster talked about how it took about 48 hours for them to raise the pH from 7.2 to 7.8. So that makes me feel like I can let it go overnight. Tomorrow I'll more aggressively lower the pH and get back to aerating. I'm aiming to get my TA down to around 50 if possible, which is the low number on my scale for my pool. Then I'll get to work on the borate thing. But I've got a long road ahead of me first I think.

 

[MarianParoo]

Yes. Please don't add borates until you are way stable (like a month or two) with pH/TA. Borates are terrific when you are balanced but can be very difficult if you start too early as pH/TA are harder to adjust with borates.

Also, borates are like CYA and CH. You can't lower them easily.

 

[pooldv]

Try lowering it to 60 first, it might be good there since you don't have SWG. Try it for a week or two and if your PH still rises then drop to 50. Sometimes 50 is too low for some pools and PH becomes erratic. Although 50 works great in my pool and many others.

 

[camueller]

Thanks for the tips, all. I already bought borax, but it can sit in my storage room until I need it. It is apparent that this is going to be a long process anyway. I let my rig run over night, and my pH is up to about 7.6 now. After we swim today I'll drop it to 7.2 and aerate overnight. Keep doing so until my TA gets where I want it.

And just so I'm clear, I'm definitely aware of how the borates don't come out of the water...just like the salt I got talked into adding to my pool to keep my eyes from burning, and the CYA that was already sky high in there from the previous owner of my house, and the calcium from the awful water our city distributes. I've come to terms with many things

Much appreciated, all! I'll get there eventually.

 

[Richard320]

Is that pipe open ended, so it's a geyser? If so, try capping it with something more like a sprinkler or showerhead so you get greater velocity and more surface disturbance.

I'm lucky in that I have a spillover spa. When I run all the return flow through it, the surface almost looks like it;s boiling. I was able to drive pH back up in a couple hours. It's the frothing that really gets things going.

 

[camueller]

Is that pipe open ended, so it's a geyser? If so, try capping it with something more like a sprinkler or showerhead so you get greater velocity and more surface disturbance.

I'm lucky in that I have a spillover spa. When I run all the return flow through it, the surface almost looks like it;s boiling. I was able to drive pH back up in a couple hours. It's the frothing that really gets things going.

Thanks for asking. It is uncapped and just spills out like a geyser. Perhaps I'll run to the hardware store today and get a cap and drill some holes in it to make a shower head sprayer. It'll look cooler that way too! I meant to ask about that before, and forgot.

One other question: should I be running my pump 24x7 while aerating, or should I just let it run at the normal schedule? Since I'm not relying on it to push the water, I'm not sure if it matters. Though keeping the water stirred up makes frequent testing easier.

 

[Richard320]

Thanks for asking. It is uncapped and just spills out like a geyser. Perhaps I'll run to the hardware store today and get a cap and drill some holes in it to make a shower head sprayer. It'll look cooler that way too! I meant to ask about that before, and forgot.

One other question: should I be running my pump 24x7 while aerating, or should I just let it run at the normal schedule? Since I'm not relying on it to push the water, I'm not sure if it matters. Though keeping the water stirred up makes frequent testing easier.

I wouldn't waste the electricity.

 

[Sidecarist]

When I went through the same process I was surprised at how much better it worked to lower my pH to 7.0 then raise it to 7.4 and repeat that process. I did it during the week so 0 swimmer load, but aeration raised the pH from 7 to 7.4 in about half the time it took to go from 7.4 to 7.8. I was using a spa jet in one of the returns. It worked great.

God luck. It's worth it. My pH has remained rock solid at 7.5 for the last month even with the SWG.

 

[camueller]

That's interesting Sidecarist. It is hot and we swim quite a bit lately, so I'm not sure I want to go that low. But I took it down to 7.2 earlier this evening and after modifying my aerator setup to have a cap on the end of my pvc with several smallish holes drilled into it, my pH is rising raster I think. I checked it a while after adding MA to knock me down to 7.2 from 7.8 after a large swimmer load earlier today. I guess all the splashing from the kids aerated for me a bit. Anyway I was already up to 7.4 after an hour or two, which is much faster than I saw last time. We'll see. I look forward to turning this thing off. I keep thinking it's raining outside.

 

[camueller]

I have another question, more towards the borates. If my fill water is high in TA, am I going to regret adding borates if I'm having to add water from my hose all the time due to evaporation? I don't know that I'm going to have to add a lot, but I suspect that I may. And I know adding borates makes adjusting the pH and TA harder. Right now I'm planning on taking the TA to 60 and seeing how things work there. But if I find I'm constantly having to fight my TA, is adding borates a bad idea?

 

[pooldv]

No, my fill TA is fairly high and it isn't a problem.

The reason it is faster to raise PH from 7.0 to 7.4 than from 7.4 to 7.8 is because the PH scale is logarithmic and the farther you get from center (7.0) the bigger the jump is. 7 to 8 is a 10x jump, 8 to 9 is a 100x jump, 9 to 10 is 1000 and so on.

It is fine to lower your PH to 7.0 briefly during this exercise. 7.0 is the rock bottom that PH should ever be allowed to be and not for long (not days, hours is OK).

 

[camueller]

Many thanks! That makes me feel better about the path I'm on. I've got my TA down to somewhere between 125 and 150 ppm now. My aerator is working much better at raising the pH back up now that I capped it and drilled the holes. I'm tempted to redo it though, and make it so that it is shooting the water down at the surface of the water, rather than up into the air. That way I'll lose less water. Will I be going backwards though in terms of productivity in raising my pH?

Knowing that a good hard rain will raise my pH by aeration, I'm guessing that the more drops of water I can get to land across the pool surface and create a splash, the faster this is going to go for me. The direction I spray the water shouldn't change things, right?

 

[pookiesunshine]

spraying up will also cool the water somewhat.

 

[camueller]

yeah, that too. I went ahead and changed my setup to just be a 1 1/4" PVC pipe straight up from my submersible pump into a T with 12" arms off the T and 1/4" holes drilled into the bottoms every other inch. It sits about 8 to 10 inches above the water surface and sprays water mostly straight down. I can't tell if it's working better, because my pH didn't rise much overnight. I'll see what it's at when I get home from work, but I'm worried it won't be much different than when I left. If that's the case, I may go back to the up in the air sprayer, even if it wastes water and makes me lose heat.