The Accidental Aquarist

Build From the Bottom, Up

Snails?  Crabs?  Fish? Corals?  Which types of which?

There are so many choices of marine life to incorporate into your tank, it’s tough to know exactly where to start.  We had a blowout once that involved over-loading the tank, poisoning it with ammonia and killing most of the corals and all of the fish.  There were a number of contributing factors that led to this melt-down, but in part, I blame the process by which we chose our fish, which was really no process at all.

Perhaps it would matter less if we were less concerned with maintaining as much natural stasis as possible.  There are plenty of chemical solutions to help you balance out your tank, and they can get you past a rough patch if necessary.  But sooner or later, it all comes down to balancing the biomass in your tank, so chemicals while helpful are really no solution.  Our feeling is that keeping things as natural as possible is really what we’re after in the first place: a show tank emulating the reefs of the world.

What seems to be working for our tank now – and what seems intuitively to make sense for all tanks – is a kind of bottom-up approach to picking out your marine friends.  This is probably not the most fun-filled process for those of you who really just want fish, but if a natural balance is what you want, this seems the way to go.  Moreover, even fish lovers may discover new joys in playing around with different species.

From The Bottom Up

The bottom-up approach means working on your cleanup crew before the fish.  Once you’re salinity is OK, your live rock is cured and your nitrogen cycle balanced, it’s time to introduce some snails.  The nice thing about snails is that you don’t have to feed them: there will never be an occasion when you’ve run out of algae for the to eat so long as there’s a possibility of life in the tank at all.  So get yourself some snails, maybe one snail for every 7 to 10 gallons your tank holds, and let them begin the process of cleaning the tank up.  We use turbo snails from Mexico, along with one turban snail, and they seem to be doing fine.

But snails aren’t enough.  Hermit crabs or some other more mobile animal will also be needed.  We’re continually surprised by the speed of the snails, but they aren’t nearly as efficient as crabs and best of all, crabs will also eat meaty foods once that becomes a necessary thing.  We’ve got three red-legged hermit crabs, but we’re thinking we want a few more different types as well.

Porcelain crabs are filter feeders, stripping little microbes and such directly out of the water around them with a couple of fan-like claws.  They’re not going to get anything out of the bottom of the tank, but they will help keep the nutrients in the water to a healthy level.  Cleaner shrimp and blood red shrimp help keep things from getting left on the ground, but they don’t deal well with high nitrate water or warmer waters.  Still, they’ll help keep your fish happy and healthy when you get around to getting fish by removing dead scales and parasites from them.

Once you start thinking about fish, bottom feeders and smaller fish are probably a better choice.  We had a problem with red slime algae, needed to keep the nutrients down and the sand mixed up to prevent the slime from returning.  As a solution, we got a diamond goby for the tank.  This goby is one of the filtering type of fish that scoops up mouthfuls of sand, eats what’s good to eat, and spits out the rest.  They’re perfect for stirring up the sand at the bottom and our sand has really never looked cleaner since we’ve had the tank.

The big thing is: diamond gobies are good bottom feeders and require barely any food to survive, relative to other fish.  The reason for the low-food requirement is simple: while other fish eat some food but let the rest fall to the floor, the diamond goby is only going to eat stuff off the floor, anyway.  Therefore, top-swimming fish may eat 30% of the food, but bottom feeders are more likely to eat nearly 100% of the food.

Along the way, we’ve added in corals and such for the sake of decoration.  Most of them tend to be fed by the photosynthetic zooxanthellae living within them, but they do play a minor role in filtration of the raw materials present in the water.  The mushrooms we got do not have any photosynthetic cohabitants to feed them and so they’ve played a large role as well, despite introducing what we think was the cause of a recent hair algae problem.  What we want to see happen is that when we feed the fish that swim near the top, the food they don’t eat should barely hit the floor before something eats it.  Fish and other creature pooh is toxic, but it’s not as toxic as dead things rotting on the floor of your tank.

If anyone has observations on this theory, its graces or its follies, I’d be interested in hearing them from the comments!  So far, it’s working well, but we’re always open to opinions.