You will have no issues at all with the gravel. Think about it, it's a possibility in the wild, there is gravel in the rivers of South America...generally what I've noticed first hand is that if a Tig or any fish for that matter gets gravel while attempting to get food it filters it out through their gills or if it's bigger spits it back out. I've kept Tig's for years in sand blasting gravel (very fine gravel) and on river rock bottom tanks without issue. Hope that dispells any rumors and whoever told you that was a major issue clearly doesn't know what they are talking about.
The issue of water quality and flow however are notable and should be addressed.
Ok thank you, it makes me feel alittle better. Water quality should be good, my mm pups are doing just fine and flow should be good but ill put another jet in for sh*ts and giggles.
