[Discus]

hi there basically i got this gravel in my 72 gallon tank that is a sand type... just went to do a water change and noticed it all gets sucked up.... if it you need to know my stats of the tank i am talking about its 72 gal tank with a 20 gal sump with a rena xp3... if that helps you help me... just please tell me how to do a water change succesfully... just added some water in the recent change and some chemicals but want to do a full change... I fugure you could just do some top little bit of the gravel maybe?

 

[Adz1]

with the sand you shouldn't need to vacuum into it.
fish waste and dead plant matter should all be on top of the sand.
just skim the top of the sand enough to pick up the waste.

 

[Clownloachlover]

slow down the flow rate of your vacuum by putting a ball valve inline of the drain hose that you can control...dial the suction down enough to just suck up the waste and not the sand...

 

[pieces71]

your sand is heavier than the fish poops and as Adrian says poops stay on top of the sand substrate,use your vaccum low enough to suck the poops