Automation for pH control

[tloomos]

I think it’s primarily a safety and ease of installation choice. Return plumbing can get complicated with pool/spa combos, waterfalls, deck jets, etc. and you want to ensure that the acid injector will always have water flowing past it no matter what particular feature is running. You don’t want a “dead pipe” with acid being injected into it accidentally. As a manufacturer, Pentair has to “design for stupid” because you can never know just how dumb people are …

I have the acid pump relay powered by the filter pump relay - to help ensure that the acid pump can only get power if the filter pump is running. I also have the injector on the return side before it gets to the split and valves for the pump vs the pool. Just to be safe, I changed the setup so that the acid feed runs when the SWG does not.

 

[cpachris]

@cpachris, the type of acid dosing system that might be best for you might be dependent on your existing (or planned) equipment (SWGs, automation controllers, timers, etc). If you could fill in your signature, you'll get better advice. Something like mine is ideal.

Signature greatly improved now. Appreciate the suggestions.

Geday Chris and welcome to the forums.

What pH are you targeting?

Thanks @AUSpool. I was originally targeting 7.5, but have moved that up to 7.7 to be closer to the TFP recommendations. Acid needs have slowed down some. But I'm still going to look into some automation for this area because my wife and I do travel a bit, and I don't want to hire help for the pool while we are gone.

@tloomos any updates on your system? Appreciate all the input on this thread. I've learned a ton.

 

[tloomos]

@tloomos any updates on your system? Appreciate all the input on this thread. I've learned a ton.

It's been working flawlessly so far. I originally had it set with a high point of 7.5 and a hysteresis of 0.2, so it would turn on at 7.5 and off at 7.3. Now I've bumped it up to 7.7 on the high side.

The chemical feeder is running when my pump is on a fairly low speed setting, so I've found it takes a bit for the acid detection. Generally I've seen it drops 0.1 below what I have targeted. I'm going to play with that setting this week to see if I can dial it in to maintain a tighter range, but I've been very happy with it so far.

I know the TFP community frowns on anything other than chemical tests, but I have a Sutro that takes readings 3 times per day and you can see the pump working in the image below. I do the chemical tests once a week and I've found the Sutro to be accurate enough for monitoring during the week.

 

[Dirk]

I know the TFP community frowns on anything other than chemical tests, but I have a Sutro that takes readings 3 times per day and you can see the pump working in the image below. I do the chemical tests once a week and I've found the Sutro to be accurate enough for monitoring during the week.

That's a perfectly respectable MO. Yes, we like chemical tests, but many here use various types of digital pH meters. I've never used one, just haven't been interested. I test once a week anyway, and I don't want to fiddle with batteries or pH meter calibration. I doubt I could test any faster with one, the Taylor pH test is pretty easy and fast. pH meters are great for people that struggle with the color matching due to eye issues, so there's that.

 

[Dirk]

Signature greatly improved now. Appreciate the suggestions.

Thank you, looks great. You're pretty locked in to Hayward, so there's no great advantage in using a Pentair IntellipH. You'd only be able to use the tank, not the controller, though they do sell the tank separately, so I wouldn't say you shouldn't get one. But you wouldn't be able to make use of the safeguards provided by the IpH controller because you don't have a Pentair SWG. So check out Stenner acid injection solutions, but keep the Pentair acid tank in mind, as it does have some niceties not offered by Stenner.

 

[cpachris]

but I have a Sutro that takes readings 3 times per day and you can see the pump working in the image below. I do the chemical tests once a week and I've found the Sutro to be accurate enough for monitoring during the week.

Since I started googling pool stuff, I'm getting ads for the Sutro, and other devices, continually. Big Brother is definitely watching. I get instant pH and temp reads from my probes already, but it would very nice to get FC and TA. I'm probably going to go that route eventually. Anything that would make me less nervous while traveling is probably money well spent.

Thank you, looks great. You're pretty locked in to Hayward, so there's no great advantage in using a Pentair IntellipH. You'd only be able to use the tank, not the controller, though they do sell the tank separately, so I wouldn't say you shouldn't get one. But you wouldn't be able to make use of the safeguards provided by the IpH controller because you don't have a Pentair SWG. So check out Stenner acid injection solutions, but keep the Pentair acid tank in mind, as it does have some niceties not offered by Stenner.

Appreciate the advice. Will check out Stenner.

 

[Dirk]

would very nice to get FC

Yes, it certainly would be. We'd all LOVE that. But there is no such gizmo (reliable, and reasonably priced, gizmo, anyway). There is a next best thing, but it is a distant next, so we've mostly all resigned ourselves to Taylor's FAS-DPD FC testing.

Poke around here for threads about "ORP" to get a sense of what is available and whether it's something to pursue or not.

Edit: added "reasonably priced" to reflect @JoyfulNoise's post below.

 

[JoyfulNoise]

You can get free chlorine probes … they cost a couple of thousand dollars a pop and would probably need to be changed every year or so …

 

[cpachris]

You can get free chlorine probes … they cost a couple of thousand dollars a pop and would probably need to be changed every year or so …

Ouch. Free for $2k.