First Water Change

We did the first of our regular bi-weekly water changes today. We also cleaned the sponge filter and replaced the activated carbon.

It's recommended to replace 10% of your water every two weeks to keep it clean and to decrease the levels of any unwanted elements (such as nitrates) while replacing the wanted elements (such as calcium).

With our tank, that equates to replacing around 3 gallons of water. We used the aquarium vacuum to suck out the water and then replaced it with salt water that we mixed in a water container. The new reef salt we are using seems to be much better, our mixture had 480 ppm calcium and read 9 dKH. The old salt had around 300 ppm calcium and 11 dKH. The desired level of calcium is between 400 and 500 ppm and the desired level of alkalinity is between 8 and 12 dKH, however, many of the experts I've spoken to said they like the alkalinity to read around 8 or 9 dKH.

We also found our first casualty today. When we were vacuuming out the tank, we noticed a half-eaten hermit crab body. I hadn't been able to find all 5 of our hermit crabs in a couple of days, so that answers that mystery. I don't know how it died. I'm hoping it was the act of another hermit crab in the tank and not something wrong with our water parameters.

Lessons learned about making salt water for water changes:

The salt takes a while to dissolve in the water container, so the reading of 1.025 on the refractometer (which matches the salinity of the water in the aquarium), later reads higher once all the salt dissolves. We tried to mix the container well, but when it was added to the aquarium, the mixture raised the salinity too much. Next time we'll wait longer before we add the water to the tank.

We need a small water heater to heat the water in the container so the temperature matches the water in the aquarium when it's added to the tank.

We also took out too much water because we measured it in batches, and when you do that while the water is syphoned out of a tube, you waste a lot. We'll need to get a 3 gallon water container that we can fill in one shot.

It's good we did this before we added the first fish, so that next time we'll be spot on. Hopefully we'll be adding a royal gramma on Monday or Tuesday.