Concerned about my tanks

[Aennedry]

Hello everyone. I am writing in because I am concerned with some events in my two tanks and I hope I can get some help. I have two opae'ula setups, my starter tank of 2.5gal from March that I started to see how they were. It contains Mustafa's opae'ula(ten of them), his brackish snails and chaetomorpha. I feed it a fragment of a algae pellet maybe every six weeks. Gravity 1.008, temp 66 fahrenheit. My second tank has been up since September. It is a 5gal, containing around fifty shrimp ordered from Texas, including one little larvae. Tank was set up using the chaetomorpha and snails from my starter tank. Since it was a newer tank with larger number of shrimp, I was feeding this one a bit of alage pellet once every three weeks. Gravity 1.016 and temp 66 fahrenheit. Both tanks contain aragonite sand, lava rocks and shell pieces.

There was good activity in both tanks for months, many snails, food always consumed. This last month activity has decreased greatly in the 5gal and there has been a decrease in snails in both tanks. There is still shrimp activity in the 2.5, but I am seeing few shrimp running around in the 5gal. They are still sitting around on the rocks, but only a fraction of the number in the tank.

Is there something that I need to change? Is the water too cold? I have stopped feeding both tanks. Top offs are always with RO water. Have not seen any little shrimp corpses, or empty snail shells.

=^._.^=

[Mech]

test your water with a saltwater liquid test kit.

[Varanus]

Its possible that the food within the tank (biofilm and such) has simply increased to the point that the shrimp don't need to move around much to get enough food. I recall a member here who put in some ocean rocks with a lot of organic matter unknowingly hidden in them and ended up barely seeing the shrimps for months as they focused on the food in the rocks. You might try decreasing how often you feed the larger tank.

When you feed the larger tank do the shrimp get excited and come out in large numbers? How quickly do they consume the pellet? This is one way to judge their appetites.

Given you haven't seen any dead bodies I doubt there are health problems, but like the above said, you can always test the water for ammonia and such.

[Mustafa]

Varanus is right...too much food can cause such behavior. Not only do the shrimp not have to run around look for food anymore...but too much food may actually cause invisible (and sometimes visible) bacterial blooms and otherwise adversely affect water parameters.