I had a few ppl ask me what steps there are to this process so heres a quick run down of how I did the switch.
First off gotta turn off the filters so sand doesnt ruin them. I tried to first leave the large rock in but that wasnt working so i removed all the large rock and plants and left the water as it was,(ill get to that in a min). I left the fish in the tank. then with a large net i scouped out all the old gravel and put it in a hevy duty garbage bag. believe it or not you can get just about all of it out with the net except for some really small rocks. then I took a gravel cleaner and removed the large plastic part so it was just the clear hose. I then siphoned all the little rocks left in the corners out with ease. doing that brought the water down to the level i usually bring it to for a water change. Just wash the sand real good in a bucket i did 10 lbs at a time removing all the loosers grains that float to the top dumped out water in the bucked and submerged the bucked into the tank to and poured the sand in keeping it low so theres not to much stur up. wait about an hr or so for it all to settle, then skim the very top of the water cuz there will prob be some floating not much tho. turn filters on put ornaments back n ur done. sounds like a lot but really not that bad. Good luck , let me know how it turns out.
And thanks about the tank
