Substrate for Loaches

[Goldiefinn]

I recently upgraded from a 75 gallon (freshwater) to a 150 gallon tank. Inhabitants include:

1 adult Gold Severum (8")
12 Black Skirt Tetras
7 Giant Danios
1 Platy
1 BN Pleco, approx 4"

I LOVE clown loaches and now that i have a 6-ft long tank, i'd like to get a school of them -- maybe 6 or so? However, I also want to have some fun with 'eel-y' type fish and considered getting a Ropefish -- although the stories of them escaping the tanks has scared me off a bit.. so, i'm thinking maybe Weather Loaches? they are a bit eel-like..

My question is -- how critical is substrate for loaches? I have a pea-size aquarium gravel in my tank and have no plans to switch to sand... will loaches be ok? Only certain types of loaches?

I am a responsible pet owner and don't want to subject my fish to an unsuitable habitat

 

[Goldiefinn]

BTW, lots of filtration -- a Fluval FX5 and Eheim 2217 (the one I moved over from my established 75 gal)

 

[Maypea]

I switched my substrate to sand but my clowns were just fine with gravel substrate before that. They can have either, they're pretty flexible on that one.

 

[fishorama]

Gravel can work, I liked to deep vacuum it, 1/4 each Water change. A note on weather loaches--they like much cooler water temps than clowns so not ideal.