[djnzlab1]

HI,
I subscribe to the Ron Schimek theory of DSB"S and he mentioned that sand can break down to mud and thats good, My guess is some of the sand may eventially be used up or dissolved so adding a little once a year may help to replenish that calcium thats been used by the water,
there's two distinc therories onsand maint, I prefer the one with the worms no starfish . It can become extinct as any thing can in nature , things like bacteria have a limited ability to reproduce from the same gene pool for ever so , I try and re-seed my tank with a little amount live sand from a healthy tank maybe every 6mos, this will intraduce a few million new species of bacteria many tank crashes may be due to extinction of worms and other critters.
SOme experts even sample the sand bed from time to time to insure the sand has healthy mix .
That does require some equipment.
The big down to seeding is the risk of intraducing a parasite to your system.
Doug
I did have a little ich out break and all my fish seem immune now, my guess is the ich is there but the fish are immune, any new critters will get ich and require feeding of spirella loaded with garlic as long as the eat they seem to get immune after a couple months.