Zeus, what did you dial your CO2 back to? Do you now aim for a 1.0 drop or higher still? Did your plant growth take any hits from reducing the amount? I know you've improved the flow, but I'm curious if the plants that were previously in a good flow got effected by the reduction?
I cant remember how much I dialled it back but the DC was light green, I think the pH drop was reduced to about 1.3pH. With having a duel stage reg duel Solenoid/needle values and reactors it was very simple I just reduced the working pressure as counting the BPS was a little pointless.
Once I had reduced the CO2
working pressure it took 30mins to get the target pH drop I was happy with at the time, before that it took 20mins. When checked the pH wasn't stable from lights on till CO2
off so instead off reducing the CO2
injection rate on that line, I added a little timed loop on my PLC
so the CO2
injection was on for say 10mins then off for 30 seconds and fine tuned the on/off loop till it was stable. Having a PLC and a duel injection setup made getting a stable [CO2
] very easy compared to a normal single timer/injection setup.
The tank target [CO2
] was well reduced in the Covid lockdown once my CO2
cylinders got low to very low levels as I could not get CO2
. Reduced the lights and ferts at same time as well. Have since retired and moved and once moved the tank has been low tech since.
When I fitted the Gyres the plants just improved, it may of been lower [CO2] but the CO2 was delivered faster to the plants. Hygrophila pinnatifida never did well which i think was due to my very hard water.
The trouble with going for High [CO2
] is when do you cut back if there's an improvement and how much do you cut back. Esp when you have a busy life at the time. It works so you continue. I would advise to always work on improving the flow once your at a lime green DC/1.0pH drop and your still having issues. Its just easier on most setups to dial the CO2
up a bit and improving the flow/turnover is harder, so we take the easy route as I did as my twin sparbar was maxed out
Plus ugly with pipework- which took 4-6hrs to clean.
My next high tech tank will be different again plan to use RO water, present house has a well so RO water will be relatively cheap compared to being on a meter where you pay per cubic meter twice once for supply the water and then for waste, which was one of the reasons I worked on the IFC remineralising sheet ( soon to be released). I do believe that remineralised RO water will enable me to achieve better results with some plants. I was never able to get Hygrophila pinnatifida to last more than 9 months with my hard water.
Think the vid below demonstrates the flow well
Getting good/great flow at substrate level in a three sided tank was the trick to the carpet which was over 50cm below water. It even had some MC in the carpet which got limited light and no elongated internodal stems the flow at the substrate level was so good.