Hi guys, I was wondering if I should buy a watchman goby or a twinspots goby for my empty 20gal tank. I heard that a watchman goby is a little more easier to take care of compare to the other one, but I seem to like the twinspot more. I had a twinspot before and it mysteriously disappear without a trace, well actually I did found his botton fins after two weeks of his disappeareance. I don't know if my arrow crab might be the cause of his death(kind of big). I am afraid if I get the same one, it might die again. I guess my question is, how do you feed them while having your fliter on while the filter constanlty suck in the food particle suspend in the water without giving it a chance to setting down into the sand so the gobly could get to it?