Fluval Stratum substrate for Siren?

[Catnkit]

I have my lesser siren on large smooth river stone, way too big to eat. I know regular gravel is bad, it's rough and my baby will swallow it until he's pooping out half the floor. But I know he wants to dig and so that leaves me with two possibilities...

Sand - ruiner of filters, or
Fluval soil - soft and messy.

I don't want to run the possibility of him eating either of those two and impacting though, so I'm not really sure what to do. Stick with river stone to be safe, or try something softer and all the mess implied and possibility of him snarfing it?

Knowledgeable opinions appreciated.

 

[snakeguy101]

I have kept them on sand with no problems. What kind of filter did you have? Sand will not cause problems for any set up with an overflow style intake.

 

[Catnkit]

I planned on switching to a submersible so I can feel better about the lid being sealed off.