I was thinking about starting a HOB refugium for a 35 gallon FW tank. I've seen these used for SW and was wondering if a HOB FW refugium would even do anything. Let me know if you've had any experiences with this.
Yep, I used pea sized gravel for my substrate and a pre-filter sponge on the intake so the substrate wouldn't collect as much detritus.
I grew philodendron, bamboo and a few other terrestrial plants. I like cattails better as thye uptake heavy metals along with alot of nutrients. (plus you can find them free).