I dont have any fancy equipment for diffusing CO2 into my tank.
I'm using the DIY CO2 method.
There is a little point on the top of my wall filter (Dolphin F1200), where I can attach the tube of my DIY unit too. But it appears as if the CO2 just gets blown out of the filter along with the water. It seems like the CO2 then just goes almost straight to the surface and out the tank, and doesnt get diffused into the water. This is not a good way of diffusing the CO2 I'm guessing...
What Can I do? Is it okay if I attach a air-stone or sponge to the end of the DIY unit's tube and place it in the bottom of my tank?
You can put the output tube of your DIY CO2 directly beside the input tube of your Dolphin f1200. In that way, eventhough you do not have a ceramic diffuser, your wall filter will act as a CO2 reactor at the same time your filter. The problem with CO2 is it has higher density than ordinary oxegyn so diffusing with ordinary airstone is not very effective. A diffuser made of ceramic would do the work perfectly. It would help if you use your airstone and put it beside the input pipe of your HOB to further break your bubbles before it enters your filter.Have fun