Not sure what I'd suggest, 126... especially if you're hitting pockets of H2O2. Pew! If it were me I'd probably do the same as I suggested for OP - take everything out and put it into another vessel and do a major overhaul on the display, thus not risking your livestock when you inevitably open the can of stank.
I remember about 10 years ago when the DSB craze was in full swing, I had friends more learned than me shaking their heads at me for not jumping on board. I'd always done the shallow sand/vacuum method, which has worked well for me, so I took the, "If it ain't broke, don't fix it" approach. About 3 or 4 years later, when those same folks started yanking their DSBs because of leaching problems, I asked one, "How's that workin' out for ya?" - he wasn't a happy camper :lol: (But he's a good sport or I wouldn't have razzed him about it.)
It appears from anecdotal experiences, that the DSB works well for a period of time, but once it's saturated/exhausted, if it's not replaced/replenished, then the problems begin.
In my experience, doing the shallow/vacuum method doesn't present any long-term issue. You'll lose a bit of sand from vacuuming, but it's easy enough to replace some if the bed thins a bit (I like the bagged live sand for this - no muss, no fuss, no cloudy water for more than an hour or so).
A lot of the folks I knew that had discarded their DSB went the other extreme - bare bottom. And for a while the "Starboard" bottom was popular - they covered the glass bottom with a product called Starboard which was some sort of boat product so one didn't have a bare glass bottom. That fad seemed to have died out too, in fairly short order.
The trick to vacuuming sand with a gravel vacuum is to crimp the hose to control flow. I'm right-handed, so I use my right hand to manipulate the gravel tube through the sand, and I use my left hand to crimp the hose to regulate the flow. I don't really run the siphon wide open when I'm vacuuming sand, I pretty much always have the hose crimped to some extent. If sand starts to go too high up the gravel tube, I crimp down to slow the flow, sand falls back down, but I leave enough flow to suck up the lighter detritus. The finer the sand, the more tricky that is to do, but it's not that difficult with a bit of practice. You *will* lose a bit of sand here and there, but once you get the hang of it, it's not a biggie.
And for those who think that vacuuming sand will suck out all the amphipods and stuff - I just don't see that. I've inspected plenty of buckets of waste water - I've let it settle to see if there are critters in it, and there aren't. I suppose it's possible to suck up a few, but they're quicker than that - if you've ever tried to harvest pods with a turkey baster or a siphon, it's not that easy.
Jenn
