very high co2 usage on one tank

[jwmachon]

does this sound right,

I have a scaper 90 tank about 100 litres 60x38x38 roughly and 2bps hits nice green/yellow drop checker.

same co2 system on my main tank which is 90x48x45ish - 243 litres.

Both tank using same substrate, the issue is 1st on the big tank im using 11bps to get a green/yellow drop checker and 2nd starting ph 6.76 ending ph 5.80 however its taking 5.5 hours to get to just 5.93

does this sound about right for this size tank considering the smaller tank is only using 2bps.

Based on this i need to be turning on co2 5.5 hours before lights come on which seems quite alot to me.

I cant find any leaks and im using a inline diffuser on the main tank co2art

Been like this since i installed it

any thoughts welcome

 

[jwmachon]

just to add plenty of flow on both and surface movement only from skimmer so not much off gassing to be had

 

[Luciën]

Well I have a 300L+ tank and start co2 5 hrz before photosynthesis. I run a sump with reactor.

 

[Mat H]

Quite possible as it will be dependant on many factors, however pictures of both tanks could help as well as if the setups and delivery are the same i.e. diffusers, inline, reactors.

I would however recheck both the setup and moreso that the flow is good around the larger tank as I had an almost identical issue on the larger of two tanks not too long ago.

I thought my flow was good with a powerhead at the opposite end to my inlet / outlet thinking it was helping push the water back up and around, however after trying various things moving the powerhead up next to the outlet in the same direction but pointed down slightly helped ensure a better flow and CO2 distribution around the tank and particularly to the substrate level (with inline CO2) - this was also part of the fix for a BBA issue I was having.