@AdoraBelle Dearheart The other thing to remember is that you're cycling; your filter bacteria will eventually catch up, probably long before the offending fert tabs are dissolved and gone. It sounds like maybe your fert tabs are just releasing their goods way too fast, faster than your current bacteria colony can process.
Of course, ideally these nutrients don't go into the water column; they stay in the substrate and feed your plants. For whatever reason, yours aren't working that way. Adding a bunch of ferts to the water column is essentially the same as adding a bunch of fish: It takes time for your filter/substrate bacteria to catch up with the larger amount of "nutrients" (I love that euphemism; it sounds so...scientific!). In the presence of all that food, though, their numbers will rise to the occasion.
Sorry, that was long-winded, and you already know all of that. The point: It seems to me that digging out the pellets will just dislodge a bunch more nutrients, and you'll almost certainly miss a bunch. If 'twere me, I would push any pellets I can see as deep into the sand as they'll go to slow the release of nutrients. I bet it won't take long before those beneficial microbes kick in and do their little detoxifying thing.
