I've never used Bio-D personally. There are people on here who use it and have great looking tanks. There is also some reefers on here who dose Vodka/MB7 regulary while only dosing Bio-D as a boost every once in awhile with good results. I guess they do it to increase different strains of bacteria but I'm not positive on that. Once you get reading you'll see people mixing different batches of stuff all the time. But its all still pretty new to the hobby so its hard to tell what the future of their tanks are down the road.
Bio-D is kinda expensive to start up but the doses get lower as you go. The same as Zeovit. Zeovit is really expensive if you get into it with everything they have to offer. Fuan Marin is another pretty good product too. Its along the same lines of Zeovit and can add up pretty quick. MB7/ Vodka is about the cheapest you can go with a bateria driven system though hands down. But you can also make the hobby as expensive as you want too. LOL. Just like what Dave is doing, you try to manipulate the coral colors a bit to your liking. Daves tank looked great without dosing but he has to make it better
which makes it a little bit more of an expensive hobby. LOL
I told myself I would try the Vodka/MB7 method but I wouldnt go as far to dosing other things to my tank like sugar, or Bio-digest, etcc, Im sure it all out competes beneficial bateria thats naturally resides in/on live rock and such too. Thats just me thinking though. Just seems like the more you put in, the more it will accumulate in the tank at one point down the road and cause problems. Most people change water, not rocks and sand and thats what usually absorbs everyting. But that just me again.
To be honest I would only dose Vodka if your phosphates or your nitrates are out of whack.
You can dose MB7 alone just to achieve clearer/cleaner water and dont really need to dose vodka at all unless your wanting to drive down your nutrient levels. Vodka is whats going to fuel MB7 to muliply in the system to make it a more active bacteria so to speak.
I dosed MB7 for 1 month prior to dosing Vodka just to get a feel for it(yeah I was a puss). I noticed my water was literally twice as clear and it also improved skimming with MB7 alone. I started dosing Vodka and really the only thing I noticed was a little more skimmate and the algae on the glass takes a little longer to grow vs. dosing MB7 alone. Last week I only had to clean the tank sides once. And it was only little blotches. Not a big chore like it was before. It get more of a whiteish/clear fuzz patch vs. the brown green algae on the tank. Incication its trying to grow but the V/MB7 is out competing it. I was also checking my water/ test kits with Daves just to make sure everything was good.
But if you decide to start, just monitor your tank parameters closely and pay attention to your tank . Those indications will let you know whether to up your dose or back off a bit. You'll get a feel for it. Just gotta take it slow and one step at a time. Dont think more is better.Read as much as your brain/eyes can tolerate and ask as many questions as you can. I've asked some real doozies'.. As soon as you get it all figured out there'll be a "new method" to try out that everyone will jump on I'm sure. Just like the thread I was reading the other day a guy was using stump remover in his reef tank to drive down nitrates and it was working. Who would'a thought?