18" cube equipment questions
I’ve been out of the hobby for a while, but I’m thinking of jumping back in with an 18” cube planted tank. I’m looking to set up a heavily planted, mid to high light tank with CO2 injection, but I’d like to incorporate some of Diana Walstad’s approaches with a soil bottom and high flow/low biological filtration. I was wondering if you veterans could share some wisdom. Please bear with me, as I’m not quite caught up with the state of the art of planted tanks.
I’d like to have a carpet of low foreground plants (e.g. HC). I am thinking of lighting my tank with an Ecoxotic panorama pro 19w LED module (12 LEDs @ 8000k). Would this give me around 50 PAR directly underneath the lights (3” through air, 15-16” to the substrate surface) which I understand to be the necessary light for plants like HC? I see that the 13w panorama module only gets about 36PAR @ 18” from the LED lighting compendium which has me wondering.
2. Water circulation
For aesthetic and safety reasons (less tubes going in and out of the tank) I’d like to get my filtration done in the tank. I was thinking of utilizing a submerged pump with a foam pre-filter pushing water through PVC rigged like a spray bar. I’d plumb it so the foam-covered intake would be in the mid-to high water column, and the spray bar pushing water about 2” above the substrate.
I would section off a portion of the bottom of the tank so that the pump can sit very close to the glass, hiding most of it below the level of the substrate. Plants on drift wood situated over the bar would hide the bar, and their leaves would hide the foam pre-filter. (Thinking of using microsorium for this. Would the light be too high?)
My main question is about the pump. I’m thinking of using a Mag-drive 2 which pushes water at 250 gph. Would this be too much flow, even with fairly large holes in the spray bar? I want good water circulation around the plants, but I’m thinking of keeping some smaller rasboras. It’d be great if this made them swim higher in the tank, but I don’t want them to be blown all over the tank. Any alternate pump ideas would be greatly appreciated.
I also intend to send a loc-line nozzle off of a Tee in the spray bar to the surface to give it some water movement. I would use a ball valve to divert most of the flow to the spray bar.
3. CO2 injection
I plan to insert the CO2 line directly into the base of the spray bar and use it as a reactor (or a venturi). Is there any reason this won’t mix the CO2 well?
I’m wavering between ADA aqua soil and a true soil substrate with a thin sand cap. I’ll probably dry start the difficult plants. Any thoughts?
Excuse the long post. Any input would be greatly appreciated.