Please share what you end up doing with it! I’m thinking maybe mosses with mine once the shrimp have migrated to their new home (though I spotted the first babies this morning, so wish me luck getting them all out 🙄)
Ive been taking a look at the sphere. and doing some scratchpad maths... As I haven't got the tools for accurate measuring, numbers have been rounded up/down
Biorb 30
With the standard filtration system, the surface area of the substrate is donut shaped as the centre has to be kept clear. This gives a substrate area of:
300cm^2
And as the standard filtration requires a very porous bio gravel, this also isn't very good for putting plants in. Water filters through the 300cm^2 porous gravel, through the course foam donut and then the finer filter in the middle and up through the pipe back into the tank. It's quite a good system in theory, as long as you don't want any plants. Although epiphytes and mosses attached to wood or lava rock could be used.
For perspective, my small 12l rectangle tank has a substrate surface area of :
540cm^2
So I have a few thoughts on this... and my initial thought is...
1. Remove the centre pipe (just a twist and pull)
2. Connect a length of air hose to the hose connector in centre
3. Place a foam donut in the bottom of the centre 'conduit', to prevent substrate getting under the grill.
4. Leave the coarse outer foam donut in place to prevent substrate getting under the middle grill
**steps 3&4 aren't essential
5. Fill with substrate of choice to approx 8cm of height (measured from the bottom of the internal filter gubbins)
**This gives a substrate surface area of about 800cm^2 - more than double the initial surface area
6. Place a normal uplift foam filter on the substrate. Connect the extended airline from step 1 to this.
I can't get the lights to work unfortunately, so some improv will be needed there