Algae and hermit crabs

Part of the fascination and education with a mixed reef system is the behavior of the plants and animals.

This system is basically a planted saltwater tank at an early stage.  A large piece of Red Dragon in the background.  In general, we don’t “fight” so-called nuisance algae and have plenty of green hair and filamentous growing.

After adding about a dozen hermit crabs to one spot on the bottom of the display tank, they quickly spread out in all directions munching away.  After about a day, 7 or so of the bunch were tightly grouped on the very top of the highest rock mowing down green algae.

How and why did they all find the same small area?  There are many rocks and plenty of algae.  Can they hear each other, or “talk” to each other?

In any event, you can see from the white area in the picture (a poor iphone pic under white/blue LEDs) that they clean what appears to be 99%+ as they go. The purple areas are encrusting coralline algae that we want.

Very nice work!  Now we just need to vacuum the hermit crab dung which is much easier than removing the algae mechanically.

The hermits were purchased from an LFS (local fish store) for <$1.00 each.

Green algae

green-algaeYou will find many so-called “cures” for green algae.

Our cure — don’t worry about it.

Don’t treat it or dose it with chemicals.
In our KIS system, we only dose fresh water to replace (top-off) what is lost through evaporation.

Ok, ok, I’ve checked the nitrates and phosphates!  In our KIS system, nitrates and phosphates are undetectable,  but we still get plenty of algae on the glass of both the display tank and external refugium.  Both tanks in our system do get a fair amount of natural sunlight.  We run the lights about 5 hours per day.

Use RO/DI water.  We do of course.

Algae eating clean-up crew?  Good luck with that.
Who cleans up after the clean-up crew?
How many snails, crabs, and algae fish would you need to make a dent and  keep algae under control?  A dozen?  A hundred?  Will some of the snails crawl back in the rock work and die from time-to-time?  How do you control for that?

The ReefKeeper is the clean-up crew. Scrape the algae off glass. Brush or blast it off the rocks and other surfaces so it gets caught by a filter sock and then clean out the sock.  Or, siphon it out.

Think about this algae as somewhat of a natural filtration system fixing phosphates and nitrates however they happen to be getting into the system.

Don’t let the green algae build-up to the point that it is decaying and releasing problems back into the water.

A good basic test is to look at some water in a glass container against a pure white background.  Is the water crystal clear, or yellowish, or grayish?

Smell the water.  Does it smell clean and fresh, or a little “mucky”?