I'm curious about the long term effects of what goes in the tank. How would two tanks differ at 5-10 years if one was kept "sterile" (dead rock, chemicals to start, no contact with any ocean), vs a tank that has rock/sand from the ocean? Would tanks be different if everything was harvested from the Gulf of Mexico, Pacific, Atlantic, others?
I've read a good bit about pros/cons from doing it either way, but they are all about starting the tank. It seems that keeping the tank "sterile" would have a vastly decreased number of different organisms, but I'm not even sure if that matters.
I would say the most eye-opening thing to me was watching a bunch of BRS Investigates. I don't think there is an easy one size fits all approach that will work in any situation. They were studying the ugly stages of aquariums, testing the biodiversity and various other things through a bunch of different types of tanks. This is when they came to the conclusion that it's less about having the most diversity and more about having the right balance of the right things. Though they link this water testing page that has just results from TONS of people's tanks, and I realize that a lot of them get into some really unique swings that work for that tank and situation, which means disaster in others.
I think the major highlights to me were:
- - The completely sterilized tank with nothing added, had no issues until the BRS team added them. So there is a chance that would have struggled with nothing because nothing was added. Though, it struggled a lot once those things were added, because it didn't have the natural predators for it, so it was able to get a stronger footing.
- - In comparison, the one with actual live rock (shipped in water), initially struggled a bit with things that none of the other tanks have because it was introduced from the ocean. Though it naturally also had predators and competitions for nutrients and space, it just took time for things to sort of get in a balance. They end up adding a bunch of copepods, which I think sort of distorts a really good view of what would have happened had they not, which really increased the bioload suddenly and caused its own issues, but tbh I think if they would have left it alone this one would have balanced out the fastest.
- -But the ones that had live sand or reef mud performed alright and had things it worked against and others it didn't. So I think it's a blend. and not just of bacteria and that stuff, but also like copepods and other just various life.
Personally, I think we have to think about it more as an entire mini-ecosystem that is unique to itself. Like Fiji, reefs aren't going to be the same as Florida reefs and would have different bacteria/diversity %/preditors/competitions, etc than the other. Just as one cove in Fiji might be completely different than surrounding waters on the same exact specifications. Maybe your "cove" has the exact same life as someone else's, but yours get a little more light, and a little less flow, because of whatever reason, so you grow bacteria X, Y, and Z instead of A or B. Maybe X, Y, and Z are really good at out-competing bacteria C or D, so you also have a limited supply of them, and that makes you struggle with dinos. Maybe A and B are really good at out-competing G and H so they deal with green hair, maybe both of you have plenty of L, M, N, O, and P so you never struggle with cyano. Eventually, you deal with a heater malfunction where yours is on, cooks N and O, and now you struggle with cyano a bit. They have a heater malfunction but theirs is left off, it gets too cold and freezes out L and M, so they also struggle with cyano. They fix theirs and the L and M come back for them, tell you how they did it, and you follow exactly as they did, but it doesn't bring back your N and O so you get some weird results they didn't get, but it gets your L and M high enough that now you don't need the N and O. So you have less diversity, but it's still in a good balance of each other, to out-compete cyano.
So yes, I do believe "diversity" can be important, but less important than say, having everything just get in a comfortable balance that you are personally able to manage, and unique to each setup. I think you could start 100 tanks with live rock, and 100 tanks with dry rock, do each of the pretty much the same, and just the simplest differences make bigger changes than anyone might realize. I think this is why sometimes when people tear down a tank and start over again, they get different results. Even if they use the same type of rock and products and everything down to a T the same, I think sometimes just luck, life, and chance play a role. Things we do that hurt us last time end up helping this time because we have different balances causing the same issue.
