MTS - Sand

I have read Trumpet snails are good for sand substrate. Has anyone found this to be true? I know from experience the can breed at staggering rates. Is there some combo of MTS and Assassin snails that works?

Sand not gravel can result in anareobic bacterial growth when sand is approximately 2” deep. Also depends on size of sand grains, look for black streaks in sand. MTS will turn this over preventing of anaerobic bacteria Anerobic bacteria release hydrogen sulfide, a toxic gas. If tank aeration is robust, the chance of hydrogen sulfide poisoning is very low. Adding mts will stop hydrogen sulfide production.
Adding assasians will kill mts over time. Then assasins will die without food source, mts return and it starts again.

Yeah. This is what I am wondering about. So if there are MTS and the tank isn’t over fed, will the MTS population stay in check?

Yes
Controlling food excess will control MTS

Any other snails that provide value and survive with Africans?

Mystery snails will survive in most cichlid tanks. They clean glass and plant leaves.
Madagascan cichlids will rid a tank of most snails.

Any local sources of mystery snails?

Usually mystery snails are available at local MAS auction. Next auction is January 18.