Some weeks have passed since adding the first couple clown fish to the saltwater tank. I even added a second fish, a yellow watchman goby paired with a pistol shrimp. I love how the shrimp burrows in the sand and the goby sets up guard. It was a great pair to watch and while the goby always had a sour look on his face, I could usually find him standing guard in one of the tunnel openings the pistol shrimp had created. When feeding time came I could usually also find the goby coming to grab some morsels. However after a few days I stopped seeing the watchman goby even though I still heard the pistol shrimp making his popping sound for which he got his name. I looked and looked, even behind my tank fearing he jumped out. A couple weeks passed and I still don't see him so I fear I lost him either from jumping out of the tank or some other unknown reason. I went to my LFS and got another one and he has been doing awesome. It only took a few hours and he was already buddies with the pistol shrimp.
The other thing I have been monitoring lately is the pH in my tank. The pH would go up during the light cycle to around 7.95 and drop to around 7.85 or even lower when the lights went out. I really wanted to try to get the pH up a bit closer to 8.0 or 8.1 as I start to think about adding some coral. The pH a bit closer to 8 and above can be a bit more stable for incoming coral in my past experience.
Here the pH before and after trying to find a simple way to have it trend a little higher.
One of the ways I have seen to get the pH up just a bit is to use a CO2 scrubber. Too much Carbon dioxide gas in the house will get into the water and bring the pH down. Some folks just open a window to bring fresh air in the house and can raise pH. Due to the weather, I will our windows shut most of the time, so the other option is that you can run so air going into your tank through some media that absorbs CO2. If you hook a reactor with CO2 absorbing media to your skimmer then the air in pulled into the skimmer after being scrubbed of CO2 and the "cleaner" air gets mixed into the tank water through the the skimmer.
Bulk Reef Supply has a general media reactor and you can also get CO2 absorbing media to add to the reactor. I added the media to the reactor, and attached plastic tubing to the air inlet valve on the skimmer. Once I turned the skimmer on you can see above the pH has now jumped to over 8.0 in the light cycle and does not tumble quite as much as before at night.
Here is the picture of the setup. The plastic tube that came with the reactor was too big to fit on the skimmer. I could have gotten an adapter, but I found another way was just to push the smaller tube inside of the larger tube. It works for now although i know there is a much more professional solution. The incoming air is pulled through the reactor, C02 is absorbed and the air is fed into the skimmer where it goes into the water from the tank. Since there is less CO2 entering the water, the pH does not dip as much.
Here is the media I use:
One other modification is to have the skimmer itself actually supply the air that goes into the reactor by adding a tube from the "IN" side of the reactor to the collection cup. I have not done this yet, but will probably try in the near future. By having this "closed" system you can get a even better bump in the CO2.
