I added a few more fish buddies to the tank today. Three Firefish Gobies, one Lettuce Nudibranch and 20 Trochus Snails. Unfortunately I haven’t yet been able to get a stable population of snails and a number of critters in the tank consider them to be prey. Trochus and Astrea snails will both reproduce in captivity and so it’s possible to have sustainable populations if you get lucky. I’m hoping that these Trochuses are hardier!
I had previously only added individual firefish as they can be aggressive towards other firefish. After talking to a person at the fish store I went with three since their aggression, like the cardinals’, is only a real problem if there is only a pair. As long as the aggression gets spread out a bit it’s all good.
I’ll never stop overfeeding the tank so I’ll always have some degree of a green hair algae problem. This is great for Lettuce Nudibranchs as they are mono-feeders; eating only hair algae. My previous one was sucked into a powerhead. I’d adjusted the flow rate of it recently and that probably just increased the intake pressure enough to overpower the nudi. This powerhead has since been removed so at least I won’t be seeing that happen again.
Before adding new fish to a tank it takes a bit of time to get them used to the new water parameters. This is done by slowly adding tank water to the water from the store, while also removing some portion. I do this via a length of airline tube with a knot tied in one end. I simply submerge one end in the tank and slowly siphon water into a container with the new fish. This takes around 15 minutes though it ultimately depends on the delta of the parameters. Fortunately the principal ones which need to be changed slowly are salinity and pH, both of which are near instantaneous tests. This is all ultimately necessary because at the fish store they are kept in very different conditions than are present in my tank.
At the fish store the salinity will be significantly lower than it is in my display tank. This kills off certain external parasites, such as flukes, but a sudden shift can put the fish into shock and can even kill them. Additionally, there will be copper (kills some stuff) and anti-parasite medications (kills other stuff) in the water. These additions will kill coral if introduced to the tank, so after acclimation the fish need to be transferred by net.
Update since when this post was started: One of the firefish died several days after addition. The other 2 are doing great though! In the future I will be keeping new additions in a quarantine tank so that I can keep an eye on them post-acclimation. While a fish may look perfectly healthy that is no guarantee that it actually is. Quarantine makes it much easier to recognize these problems quickly.