Hi all, new member here.
I have a whacky tank that I’ve been struggling to dial in. The tank dimensions are 48”x4”x4” LWH. Approximately 3 gallons. For filtration I have a Landen pura 50 mini canister filter with the in/out flows on opposite sides of the tank also have an inline pump to increase flow. I’m currently using a standard in tank diffuser positioned directly below the outflow, but as you can imagine being 4 foot long and 4 inches deep a good portion of the co2 is direct to the surface. I’ve looked heavily into alternate co2 options with no real luck. The hose size is 6mm which leaves me with no inline diffuser options. I have a yugang horizontal reactor from aqua rocks on my 120g and another on the way for a 20G. The only potential solution I’ve been able to come up with for my whacky tank is possibly a small diy horizontal reactor. Is it possible to make one for such a small volume tank? Any ideas on possible materials I could use? Thanks for your time!
Pic included is old, mini fountain filter was removed and plants moved around some.

I have a whacky tank that I’ve been struggling to dial in. The tank dimensions are 48”x4”x4” LWH. Approximately 3 gallons. For filtration I have a Landen pura 50 mini canister filter with the in/out flows on opposite sides of the tank also have an inline pump to increase flow. I’m currently using a standard in tank diffuser positioned directly below the outflow, but as you can imagine being 4 foot long and 4 inches deep a good portion of the co2 is direct to the surface. I’ve looked heavily into alternate co2 options with no real luck. The hose size is 6mm which leaves me with no inline diffuser options. I have a yugang horizontal reactor from aqua rocks on my 120g and another on the way for a 20G. The only potential solution I’ve been able to come up with for my whacky tank is possibly a small diy horizontal reactor. Is it possible to make one for such a small volume tank? Any ideas on possible materials I could use? Thanks for your time!
Pic included is old, mini fountain filter was removed and plants moved around some.

