Can't Get Co2 Levels High Enough In 225 Gallon Tank With Overflows And Sump.

I'm having the same issue. I'm running a sump, my CO2 is on point but I am using eco complete, so it's the only thing I can think of that is causing green dust on the glass and plants as the plants can't thrive in eco complete when using CO2 and high light. Good gaseous exchange is a benefit, but as you say can use more CO2, but I think that is what sump users like us may need to put up with lol. A inline CO2 defuser will help dissolve CO2 and distribute it better, I will never go back now unless it's a small tank.
I'm about to shut my tank down and start again with tropica soil.

 

I don’t see enough information on either of your systems to diagnose the problems that you describe. What are your water parameters, starting and before a water change? What are your animal stocking levels? What are your water change programs, and how consistent are you with that?

Accurate diagnosis depends on adequate information. A headache could be from tension, or from a tumor. No way to tell without data.

To me, blaming a substrate, and tearing down the system to replace it, without a thorough analysis of the system is like doing brain surgery for a headache without a scan and other indicated tests.

Of course, as always, YMMV. You bet your money and you take your chances.

 

I have a similar setup with same size tank, sump, overflow etc. I wouldn't get to obsessed about ph drops as long as plants, fish etc. are healthy.

But if really want to crank up CO2, just put your CO2 outflow into the inflow of your sump's pump and ditch the reactor. You'll then be able to push through as much CO2 as you want.

If you really like a reactor then you'll need to build a bigger one (they are easy to make).

It's true you'll need more compared to a canister setup but the benefits of a sump makes it all worth a lil extra CO2 imo.

 

Twin CO2 injection/reactors !!, I have a 500l with Twin CO2 injection/reactors and have no problem dropping the pH over 1.0 in less than 30mins. One of our members at UKaps has a 2,000L High tech BEAST with sump and overflow and he has no issues (uses lots of CO2). The answer my be in his journal

heres my injection rate



We also have some data on the CO2 used per tank size which may help also

 

On my tank, I built a three stage Cerges reactor to make sure I never ran into CO2 problems. This is what I would suggest...