rocksoutforcheese;2941255; said:we just switched to sand from gravel in our 55 gal tank and my fiance's brother is always giving him his two cents.He told him not to be surprised if we started having our fish die because sand won't hold the bacteria as well... now my fiance is driving me crazy asking me questions... he's kind of new to this stuff... definately not worried about our fish dying lol they're perfectly healthy and water is great, but could it take a turn for the worse?? is this stuff about a sand substrate true?
Assuming you had enough bacteria left in the filters and the rest to avoid a spike, which is almost assuredly the case, then you are fine. Long term, the sand actually serves as a better host to beneficial bacteria; it has far, far more surface area than gravel, even with only a thin layer that the water penetrates. Bacteria also adheres very well to it; so your buddy is off base there. With a thin sand substrate bottom, in most cases you probably have more nitrification occurring there than in most filter set ups.
