I use Easy Flow kits from the Aquarium Co op as air lift risers to my UGF plates. I have 4 of them on my 75 gallon. The 4 of them combined when the air collars are new gives 240 gallons per hour flow..
I played around with putting the air pumps for these on wifi timers. I shut them off when the co2 came on until the solenoid shut off at night. I have canister filters in addition to my ugf filtration.
I took multiple
ph samples throughout the day in half hour intervals on days I ran the air pumps non stop and the days I shut them off during the time co2 was running.
My results were no difference in ph levels were discernible with liquid drop testing. I could never discern a difference in any way at all between running the air pumps 24/7 or shutting them off while co2 was running.
I am not saying that running air driven filtration doesnt lower co2 levels at all. But I am saying running 4 air driven filtration with a curved uplift tube where most of the air bubbles come out parallel to the water surface along with the water flow in a 75 gallon tank does not provide enough surface disruption to show up in liquid ph test. I still reached ph drop of 1 from a degassed sample that was shaken vigorously for 3 minutes, and it did not take noticeably longer to achieve when air driven filtration ve Easy Flow air lift was being used and if they were shut off…. The co2 rate entering the horizontal reactor was the same . No adjustment was made.
I did not test with standard uplift tubes that might cause more surface disruption.
My conclusion was that any savings of co2 in my 75 gallon tank from turning off the air pumps would never be enough to notice in terms of how much I was spending on co2 gas in the course of a year.
Now I also run co2 and air driven filtration in a 20 high quarantine tank. Ihave UGF and a Lees triple flow box filter in that tank, all three air lifts run by Easy Flow kits. There is no canister filter on this tank. Co2 is supplied using 3 co2 bells in one corner of the tank fed by sugar fermentation reactors. There is a small 80 gph powerhead circulating water below the co2 bells.
On this tank, the co2 loss is definitely noticeable depending how much flow is being tun by the air driven filtration.. I have not done serial liquid ph testing over time to quantify it, but I do have an air blead through an airstone adjusted by a ziss microadjustable air valve that I can bleed off air from a manifold to modulate the amount of flow going through the 3 airlifts. There is indeed a discernible difference in how green the drop checker gets is dependent of the flow through the easy flow kits.
I have the flow set so that I somewhere around 12
ppm ish co2 in this quarantine tank to maintain plant healthduring tomes there is no livestock in the tank.
So, 3 airlifts lift kits in a 20 high tank yields noticeable increase in CO2 offgassing. Adjusting the rate of flow makes a discernible difference.
4 airlifts lift kits kits in a 75 gallon tank, no discernible difference.
“For a difference to be a difference, it has to make a difference..”. Gill Carson.