I used to have my Electric Blue Haps in a 75 gallon tank with Black Diamond Blasting Sand, and I liked the look of that, but the haps would dig in the sand, and the sand kept getting sucked into the filters and stopping the impellers. That 75 gallon tank leaked out a few months ago, and I just got them a new 55 gallon tank, but I don't currently have any substrate in that tank, so I was wondering if anyone knew of maybe some finer black gravel that looks good, but that isn't as fine as the sand and that won't get sucked into the filter. I typically don't like the look of gravel, but I think that if I can find some that looks good, it will look better than having no substrate at all.