How would you classify this platy?
I think Yellow Hybrid Platy is pretty close.
These have a little orange in them but the others in the tank at the LFS were more dull/all yellow.
The pumps are usually adjustable so you could control the amount of suction, but I think the prices on some of the pumps was a little expensive but its been a while since I looked.
If it is really a koi (has whiskers beside mouth) they love to eat plants so i wouldn't get the really expensive plants just to have them eaten/chewed on. Koi can also get very large so you may have to purchase a larger tank or a lawn pond in the future.
if the tube is too tall couldn't you just cut it down with a sarated (steak) knife or a hobby knife? Is the tube too tall, or do you have insufficent suction due to water pressure or a hose that is too long?
I recenty noticed these tiny white/clear things growing on the plants in my frog tank and I would like to know what they are. They eat like venus fly traps, closeing shut rapidly on particals that float by.