co2 diffusion - ladder vs rio venturi pump
I have a pretty simple 15 gallon tall tank.
Plants: sword x1, java fern, cryptocoryne x1, and h. leucocephala.
Lights: 26 W CFL 6500K on for 12 hours/day
Fish: BN pleco x1, zebra danios x2, cory trilineatus x2, oto x2, SAE x2, guppies x10, platy x2, dwarf gourami x1, harlequin rasborasx4
Inverts: nerite snail x1
I am using a DIY yeast reactor and diffusing with an airstone. My KH is 6 and morning pH is 7.3, supposedly giving me a dissolved CO2 conc of about 11 ppm per KH/pH charts. I am looking for a better way to dissolve the CO2 and I can't decide between getting a nutrafin CO2 ladder or just getting the Rio RVT 800 pump, aiming it down, and feeding the co2 directly into the venturi inflow.
I've read all the Tom Barr internal and external reactor designs, but I'm not looking to build anything at this time. One of Tom's postings mentions that the impellers on the Rio RVT produce a nice mist, so I'm wondering if that would be sufficient without an attached reactor.
Also, the inflow on the Rio seems to be quite open. As I have some pretty small fish, I would be concerned about them getting sucked in. Any solutions?