Fish Tank Wars

We went to Gulf Shores beach today with some other homeschool families from Fairhope and Daphne.  Other than relaxing, getting to know new friends, etc., my goal for the trip was to collect some seaweed and maybe other creatures for our tank (which has grown to 2 tanks: the original 20 gallon and a 5 gallon).

We found plenty of little fish in the surf and Travis scooped up a dozen or so with the net.  They were little pin fish and some glass minnows.  That was from the Gulf.  Then we went to the Lagoon and collected 2 hermit crabs, since we have not had any for a while, and a baby sand dollar that looked broken.  I wanted to see if it would rehab in the tank.  While I don’t have sand in the tank (the bottom is all small shells) I was thinking of putting in a little sand just for this.  I’ll probably fill a giant atlantic cockle shell with the sand.

After much relaxing we headed home.  By the time we got there only one glass minnow was still swimming.  I put it and the hermit crabs into the little tank; the sand dollar into the bigger one.  I was concerned about the water temperature in the larger tank being too cold, which is why most critters went into the small tank.  One crab quickly switched shells.  I had a few various-sized shells in the tank.  It went from a ratty looking tulip shell (green with algae and speckled with barnacles) to a lightning whelk shell. 

 As I watched, the fish swam around (I thought it looked happy), then it explored near the sea urchins then near the aerator then near the hermit crab.  The hermit crab clawed it.  It was dead.  Right before me, my new pet killed my other new pet.  About 15 minutes later I watched the tank again and the crab had the fish in one claw while it ripped it with the other and stuffed pieces into its mouth.

Then, it started attacking the other hermit crab which tucked itself as far as it could into the tulip shell it calls home.  Thankfully that didn’t last long and the two are scooting around the tank away from each other.  There is plenty of sea grass for the crabs to eat but now I’m worried about the urchins.  I will have to move them to the big tank. 

I thought this would be fun to have new critters to watch.  I was wrong.  I hope tomorrow is a better day.

Salt Water Fish Tank part 1

The boys had a microscope workshop today with their 4H group.  Keith Wilson, from the Extension office, taught the class.  Before looking at the samples he had brought with him (crabs, fish, plankton, seaweed), he gave instruction on how to put together a salt water fish tank.  My youngest son helped him with this.  First, he set the base and tube into the tank then covered the base with gravel.  We learned that you can use crushed shells straight off the beach instead.  tank1Add ocean water and wait 3 weeks for bacteria to grow on the rocks or shells before stocking the tank with creatures. If you don’t let bacteria grow before stocking the tank and the creatures will expell waste and the water will turn yellow with ammonia and harmful bacteria.  The good bacteria will keep the water balanced for the creatures to live in.  Once the gravel was in place, he put in the air filter and turn it on then added critters. His rocks, bacteria, critters and water had previously been in a tank and had separated them for the class demonstration.   

Keith also instructed us on salinity levels.  When the tank looks like it’s lost water to evaporation, you’re supposed to add distilled water.  What evaporates is the fresh water, not the salt, so if you add more salt water to the tank, the salinity is raised and most creatures will die.  Distilled water will replenish the evaporated water without changing the ph or salinity.  tank2

Keith gave us a 20 gallon tank to use.  We’ll set it up in the house and by the second week of December we’ll invite the 4H club over to net some creatures from the surf.  Hopefully club members will be able to come over often and participate in making it a really cool aquarium.  Keith suggested swapping out critters often.  That’s fine with me.  Someone suggested putting a shark in the tank, which would be cool, but I don’t know if I could handle living with a shark for long.  Plus, it would outgrow the tank.  A baby shark for a week or two…that’s ok. 

Tune in for more info in December.