So; things have had some interesting events and along with the aquarium arriving very late only to be made back to front it got made the correct way (after much protest) it then arrived to a sub standard which I did accept as I thought I could work with it, however when I filled it for a trial the silicone gave.
That's now another story as I think I've found the company to now build it who seem a lot more knowledgeable, have the equipment and from photos the skills - we will see how it turns out next month hopefully!
Before I noticed the silicone and had to drain it rather quick I did have chance to test the RFG (Random Flow Generator) and first signs look promising (although the hole in the correct place would have helped) link
here to a video of it running for a few minutes and prior to this few minutes flow had been all around the back of the aquarium, it really did seem to get everywhere but only testing it with stone and sand will tell. If it doesn't work it's a simple case of removing it and adding a standard Loc-Line nozzle.
CO2 is the topic at the moment, I'll base this on photos of the aquarium that went back and is
roughly how things should be just explaining the very basics. You will see in the first photo working left to right; water enters the 1st section (Weir comb missing) down through some filter foam, underneath the first baffle and back over the next to go down through some bio balls, under the third baffle then back over to the return pump section where the pump will return the water to the aquarium from the bottom of the return section and add CO2 there.
The second photo will hopefully help show further how this will differentiate from a sump and is instead an all in one/integrated filter (other descriptors welcome). The idea is that the water level stays the same throughout the display and partitioned filtration section. There are no places where the water will come cascading over baffles etc so I question how/why this would effect CO2?
The Blue line is approximate water level; 12mm from rim
throughout.
'Injecting' CO2 would be using a similar method to
@Geoffrey Rea does
here where the CO2 is diffused and sucked straight into a return pump which will break it up more then hopefully the Venturi action of the RFG will help further.
@foxfish I will try to squeeze some kind of cone in if I can but it looked a bit too tight.