Print 4 for most small-ish aquariums. I use the 25mm “speed” setting in Prusa Slicer as they don't really need to be super pretty to get the job done! They print just as fast with 100% infill due to the small size.
If you need them to be wider (for bigger fish tanks), just scale vertically in your slicer.
The author marked this model as their own original creation.