i went from a gravel substraight to sand about 3mths ago and it has been nothing but problems for me. I have gone through 5 hob's in that time span and can't stop the sand from getting spat into the intake. i have tried everything. i was thinking of doing a wet dry but i can't buy the return pump right now and my stand really won't fit anything under it but a 10gal. what have you done to prevent this from happening. maybe there is something i haven't tried or thought about.l