This is my current in progress build tank of 62 gallons. I originally had the water very murky so bad that I couldn't see my hand at the bottom of the tank so I flushed it 2x and have finally got it to where the filter can do a decent job. I'm also adding in a air pump at the other end of the tank away from the filter to increase circulation and aeration.
I did, I still have yet to put the spawning structures in place. Next one I'll look into using pea gravel or a combination of the 2.
Yep, I did the exact same thing on the sand.
One of my daughters wanted some of the cute yellow bullheads from our creek in an aquarium tank. I put the sand from their original environment in their new tank. Now every time she does a water transfer, it stirs up a ton of fines in the tank.
P.S. Lots of good threads on Pond Boss for FHM spawning structures.
Just remember that the bio filter needs about 30-45 days being charged with Ammonia to get the biological side of things working the way they should. Keep testing daily for Ammonia, Nitrite and Nitrate.