co2 24/7 is better?

[EvolutionZ]

well.. i did'nt know how should i put for the title.. i had a 2ft tank with co2 tank with solenoid. co2 was set at 3 - 4 bps.. and diffused via a ceramic diffusor. after that i tore down that tank and went for CRS.
now im backing to high tech tank. but i did'nt want go to spend so much on co2 again. so i bought a 2nd hand co2 set with manual regulator.
i set-up my tank 2 days ago. to ensure i have no algae problems. i went to buy a sera co2 test kit. i set my co2 at 3bps and with a good ceramic diffusor which produces very very fine bubbles. everything was same as what i set-up for the 1st high tech.

my co2 test kit shows me too much co2 on the label. so i went on to cut down to 2bps. it was said that co2 drop checker ned 6hours for the colouration to be stable. so now its more than 6hours later. despite being having 2bps, the drop checker is still showing yellow colour which simply means way too much co2. and my HC were bubbling as well.

SO... i went on just minutes ago and once again drop my co2 to 1.5bps.

so i was wondering. is it because i had my co2 on 24/7, therefore the co2 level inside the tank was enough, or rather too much co2 inside the tank.
Thus, i can save much more co2? i guess the drop checker will still show yellowish colour tomorrow even with 1.5bps.

PS: my sera co2 test kit i was using distilled water with kH 4. for the water in the drop checker. so i guess my co2 drop checker is accurate?

anyone can verify? cause i keep thinking 1.5 or 2bps is really low for my 2ft tank with 2x36watt PL ( 4wpg) and high fert dosing using EI

thanks

[PeterGwee]

It might be possible that the uptake of CO2 is not high as the tank is new. Is the solution dark blue to begin with? Is your CO2 rate stable or moving all over the place? Anyway, CO2 during the photoperiod is a better method as you can add more with less risk of killing critters since the plants are using it.

Regards,
Peter Gwee

[EvolutionZ]

for the drop checker, i use distilled water with kH of 4. the solution if i remember is not dark blue when i first drop the regent in. if im not wrong. its darkgreen with a litttle bluish.. should i remix?

my co2 diffusor is placed below my rainbar. so most of the bubbles are blown all over the place... is it wrong to do this?