Welcome to AA!
You have a good cleaning schedule going on. Once a week is what I recommend.
In regards to your stocking, the Pleco
grows far too big for your tank. You may want to consider taking him back to the lfs
. A smaller pleco like a bristlenose would be well suited for your tank size. If the Shark
is showing overly aggressive signs, you may want to reconsider having him in the tank. The Gourami
an excellent choice for the tank size that you are working with. If you return the shark you will have more stocking possibilities. Danios
are also great community fish.
Don't rely on the 1" per gal
guideline. It is only accurate for smaller fish peaceful fish.
I have never owned a raphael so I can not comment on his behavior.
Sand is excellent for freshwater tanks. If you are wanting to change out the substrate, I would use Pool Filter Sand. It is cheap, heavy, and looks very nice IMO
. It can be purchased at your local pool supply store. It normally has rounded edge grains so double check before purchasing to make sure it is not sharp sand. It costs (around here) about $6 per 50 lbs.
Since pfs is heavier it does not get sucked into the python as easily. I actually aquascape with the python. It pulls it up but if you turn the syphon to an angle it will fall back out of the tube.