I am currently doing some reseach on ph control for next season. We currently use acid to control ph and Pulsar briquettes for Chl. I am wondering if anyone out there has had any good or bad experiences with Co2.
We have been having some issues with safety when it comes to acid and I would like to switch to something a little safer with less chance of error.
I would caution that while CO2 systems are relatively safe, caution should be used with CO2 gas. Most of our ME rooms are below grade and CO2 is heavier than air and will displace the oxygen in an enclosed space. Unlike chlorine, CO2 in odorless, but can overcome occupants in relatively low concentrations (5.0ppm). In my experience, many pools are not installing a CO2 (NOT CO - carbon monoxide) sensor in their feed rooms, placing workers at risk if a leak is present.
Now, with the safety aside, if your TA of your make up water is high, a slow feed of CO2 will raise it even more, forcing you to dose with acid to reduce your TA more frequently. Pools that have lower or mid range levels of TA and use CO2 report few headaches with their symptoms to me. Hope this helps.
I agree with the Bruce's comments as far as safety concerns. We currently run both CO2 and Acid with just switching over to acid last year as our TA runs high and acid became the only solution. I know it can be risky but as long as you have a CPO on staff and manning the chemicals you should be fine. I would caution against only using CO2. It becomes difficult to manage with high bather loads and lots of sunshine, acid works great for us.
At a prior aquatic facility, I used CO2 and sulfuric acid to control pH. For a while we used CO2 only and has the TA increased it became more and more difficult to lower pH with CO2. We eventually re-wired the relay from the controller to power the CO2 and acid at the same time. It worked like a charm and we didn't run out of either product as fast.
I have used both with Pulsar Tabs, the CO2 can't keep up on a busy day. I have questioned the change in the Pulsar tabs, over the past couple of years it seams that they have a higher ph value. Need to pump more acid which also lowers the alkalinity in the water, causing us to ad more Bicarb That is one nice feature about CO2 it does not lower the alkalinity. Acid still seams to be the most cost affective and with the best control of PH.
CO2 is easy to use, however Pulsar tabs need a really low alkalinty range and as mentioned the CO2 will drive that up. I recommend to increase the safety awareness of not mixing chemicals, etc. and keep the acid. If you move to CO2 you will need some liquid acid on hand anyway.