Just yesterday ordered up parts for this years pool project. I have the Hayward Omnilogic system as my pool panel, and have 2 relays that are currently not being used. I ordered yesterday the HL-CHEM system (ORP and PH sensors in a test well that connect to the main panel), as well as a 12 GPD Rola-Chem pump, and the Hayward AC003 residential CO2 system.
I decided on the AC003 CO2 system because it appears that it comes with an actual gage to see what the bottle pressure is, as well as the ability to change the flow rate into the system. I have already purchased a 50 LB bottle of CO2 from a local welding supply, and I will be able to do a bottle exchange with them for about $25 dollars per bottle. Warning, the 50 LB is the CO2 that is inside the bottle, but the whole thing weights way more than that, I am using a hand cart to transport the bottle to and from my pool shed, but you still have to handle the bottle and get it in and out of your vehicle. My local welding shop offers a pickup and delivery of about 20 dollars, so that might be in my future.
I have some questions for anybody interested in answering. And after reading on this site about a lot of issues with ORP, I am wondering if I am headed down a crazy path. Regardless, it does sound like the PH part of this setup will work pretty well, and a stable PH will be welcome. My main goal here is to stabilize the pool chemistry as much as possible and keep things balanced better. If the ORP ends up not working well, I might just switch the pump to a "timer" mode and adjust that instead to keep my FC pretty close.
I will be injecting CO2 into the pool return lines, but I have a few choices as to the location of such. Since I have an AA in floor cleaner, I was going to inject the CO2 at the last PVC elbow as the water leaves my pool shed on it's way to the sequencing valve for the cleaner, which is located closer to the actual pool. I am worried that the acidity of the carbonic acid might hurt the sequencing valve?? The other choice for adding the CO2 would be the return lines that are headed for the venturi skimmers (there are 2 skimmers fed with a 3/4 inch pvc line). These lines provide pressurized return water to the skimmer to create a high flow through the skimmer, and this water actually exits about a foot below the skimmers themselves.
Would I be risking damaging the sequencing valve (not sure if there are any metal components inside that thing), or would I better be served running the co2 through the skimmer venturis?? I am leaning towards the infloor system because the CO2 would have a lot greater time absorbing into solution going through all that apparatus, and also would exit the pool at floor level... I do know that the acidity of carbonic acid is pretty mild compared to muratic. Thoughts?
Same question with the liquid bleach? I can inject it at either location, but leaning towards injecting it at the skimmer venturis. I could also inject the bleach into the same line headed for the floor sequencing valves, but when CO2 is dispensing at the same time, would the low PH in that line damage or help the effect of the chlorine?
Currently, when I add chemicals of any kind, I simply slowly pour them into the skimmers while the pump is running at high speed, this dilutes them significantly as the flow rate through the skimmers is very high, and the water just exits out about a foot below the skimmer towards the center of the pool. And no, this water doesn't return to the pump as the skimmers don't connect to the pump inlets, so my equipment back at the shed doesn't see any water that doesn't return through the main floor drain.
To be clear, my primary sanitizer is chlorine supplied as liquid bleach, however, I have an AA ozone system hooked up to the main filter pump. This is the pump that feeds the filter, and then the heater, and then the infloor cleaner and skimmer venturis (the heater is mostly bypassed 99% of the time anyway, we only throw that valve when we heat up the spa, which is rare). The way it is plumbed is a small tube sucks air through the ozone chamber and draws that through the pump impeller. There is a restrictor valve in this line so that the pump is limited in the amount of "ozone/air" that is being drawn into the impeller. What I am concerned with here is that I will be feeding water into the ORP sensor that has (in theory anyway) some ozone in it. Can anyone speculate as to how this will affect the setup of my desired ORP setpoint? I understand that there is no ORP value that is a standard, but rather I will have to adjust my pool chemistry to a desired setpoint, find the corresponding ORP value that registers, and then set that value as a target in the controller. However, the pump runs at different speeds throughout the day, and thus I would think is drawing in various different levels of ozone (in theory, again), and thus you would think the ORP value would then not be stable?? Perhaps I would be better served to just remove the ozone system completely as I'm not sure it's really doing anything to help??
I would prefer that the injection of chemicals only happen when the pump is running at it's high speed times, which are for a few hours in the morning, and then again in the evening. However, other than a few early morning hours, when the pump isn't at a high speed I keep water trickling through the infloor cleaner at about 20% just to keep things from getting stagnant (and also to draw some of my theoretical ozone into the system
So, in the logic of the HL-CHEM system, is there a flow sensor in that testing orb? Or does Hayward use the logic in the Omnilogic to know when the pump is "ON" and thus safe to dispense chemicals. I don't want to inject chemicals when the system is just in a trickle state, but rather than when the infloor cleaner is running full blast and everything can get diluted out quickly. If there is a flow sensor in the HL-CHEM orb, I don't see it, and I'm not sure there is a threshold setting to dispense chemicals in the Omnilogic. I'm thinking I might decrease the run times on the infloor cleaner, but increase the flow rate for those times to compensate? Thoughts?? Also thought of wiring in a pressure switch to prevent the system from dispensing chemicals unless there was a certain pressure in the return lines. I saw a couple of adjustable pressure switches on Amazon that I could rig for this purpose.
In any case, I'm out to the shed to start the wiring of some outlets that will serve as the plug in spots for the Rolachem and CO2 solenoid. Bought a couple of LED nightlights that I will plug into the outlets so I can easily see when each system is "dispensing" chemicals. And I will try to post some pictures of all this and more when I get more into it.
I am hoping this project goes smoothly and the results are positive. After a lot of reading my hopes of the ORP working well is questioned.
Cheers to all,