Aquarium Fish Blog

Several months ago I bought a 15 watt AquaStep UV Sterilizer for my 110 gallon saltwater aquarium and I was hoping that it would help me in a couple of areas:

• The Powder Blue Tang (Acanthurus leucosternon) was THE fish that I wanted to keep but after reading about how difficult it could be to care for them I stayed away from them. It can be very difficult to get them eating aquarium foods and they are prone to ich (cryptocaryon) like most tangs. I was hoping that the UV Sterilizer would give me a “leg up” and finally I would attempt to keep one of these Powder Blue Tangs.
• I was getting a minor cyanobacteria outbreak in the back corners of this fowlr saltwater tank. I increased water flow in those particular areas, performed regular water changes with Reverse Osmosis water and slow dose with Kalkwasser to help keep alkalinity and calcium levels at the right levels. Perhaps the Ultraviolet Sterilizer would be the straw that broke this slime algae’s back.

The Aquastep UV Sterilizer is about the middle of the road as far as price goes. After comparing several models of sterilizers and reading several reviews on them I decided to go with this one since it’s my first sterilizer, I could hang it on the back of the tank and it wasn’t too expensive. Replacement bulbs are about $40 bucks and they should be replaced about every 6 months or so if you use them constantly, which I planned on doing.

Setting this UV Sterilizer up was easy and I had to use an old maxijet 1200 powerhead that was not being used to supply water to the sterilizer from the tank. This sterilizer was setup on a 30 gallon quarantine tank that the powder blue tang was going in. After getting the tang into the qt tank, I monitored it for any signs of disease for about 5 weeks.

At first, I was pleasantly surprised to see the tang swimming well and showing no signs of ich. After several days of tempting it with the best foods I could get my hands on such as frozen herbivore cubes (thawed), brine shrimp and sea veggies, I started to get worried because it wasn’t eating anything! I didn’t get discouraged though because I knew what I was getting into when I bought this fish. For the first week it was a daily process of introducing foods only to watch this tang just look at it. At about the second week though I guess it finally got hungry enough to “sample” the sea veggies (dried seaweed) that I had placed in a veggie clip on the tank glass. Soon after, it was tagging the veggie clip as soon as it was placed in the tank.

Good deal, the tang was finally eating, but were those white spots on the pectoral fins that I just noticed? Aww Craaap! Out comes the rid-ich medication! I guess the flow was too fast for the UV sterilizer to get rid of these parasites or it doesn’t work. Whatever the problem, it was time to treat this fish. For about the next 2 weeks I treated it for ich and did small water changes, vacuuming the bottom of the bare bottom qt tank to siphon up any cysts that were on the bottom of the tank. For 2 more weeks (after 2 weeks of treating this fish) I watched closely for any more signs of disease and the fish was eating and looking great. Time to put the tang into the main tank.

After slowly acclimating the powder blue tang to the main tank’s water, I released it into the tank. It’s been doing great ever since. I also removed the UV Sterilizer from the quarantine tank and put it on the main tank, thinking that it could only help, right?

Well, there was a minor amount of green algae growing on the back tank glass and tank sides that I purposely let grow since I knew that the powder blue would be going in there. After several days of running the sterilizer, there was definitely a reduced amount of algae in the tank and the tank water seemed “clearer”. I know, not exactly scientific and it could have been wishful thinking, but that was what I honestly thought.

I’ve kept the sterilizer running and I clean the quartz sleeve about every 2 weeks. The algae seems to be kept in check but I can’t say for sure if it’s because of the tang or the sterilizer or both. The slime algae is diminished, still very small amounts in the very back corners, less than before, but still there. I believe that it may be Phormidium slime algae. It’s more of a brown color than red though. Nitrates are undetectable (used two different test kits) and phosphates are nil. I keep specific gravity at about 1.024 and the tank runs at about 79 degrees F, pH ranges from 8.2 night time to 8.5 daytime. Calcium is around 380 - 400 and alkalinity is around 2.5 meq/L. Total tank turnover is about 18 times per hour - 6 powerheads rated at 300 gph. An upcoming project for this tank is a closed circulation loop with and external pump to get some of these powerheads out of the tank and increase total water flow throughout the tank.

It’s hard to say whether this sterilizer was really worth getting. The tang bounced back from the ich in the qt tank. Maybe the ich outbreak would have been worse if I hadn’t had one? Or maybe not. It does seem to be helping keep algae in check in the main tank, but the tang could also be doing most of the heavy lifting here. I was hoping that I could be more conclusive regarding a recommendation on UV Sterilizers and maybe make myself feel better for spending hard earned cash on this equipment.