So far so good. This pump+filter on top of tank seems to be the only setup that works. In variations that had the pump+filter on the table next to the tank, leakage was a constant problem. In this on-top configuration, I’ve had no leakage problems. Yet. The opae seem to love it. They’re very active all day and night. Breeding has been taking place in the 1.5 gallon, but I think it’s accelerating under this new setup. The trickle filtering seems just about right. The 10-gallon, which I’ll be covering soon, is also set up with a single pump+filter unit on top of the tank, and it seems to be doing fine. Again, the opae are very active day and night. The 18-gallon has two pump+filter units, and it, too, is doing fine. I’ll be covering this tank soon, too.
This is a photo of the oblong 1.5 gallon.
This is a photo of the 1-gallon.
Update 3/12/17 – The setup here didn’t work out. The pumps are positioned too low, reducing the flow. I moved the pump-prefilter unit so that it now sits on top of the tank. I’ll be posting photos or a video soon. In the meantime, see the video that demonstrates this placement modification on the 1.5g oblong tank.
This is the 18g (filled to 10g) tank with Tom Aqua Lifter Dosing-Circulation Pumps attached to both UGF exhaust tubes. The Aqualifter will pump water up to a height of 30″. The input tube passes through a prefilter (Tom Suction Filter for Aqua Lifter Aquarium Vacuum Pump) before it reaches the pump. This prefilter serves as an external mechanical filter for the tank, the first I’ve used in any of my tanks. It also keeps the pump from clogging.
This is the setup. Tube1 pulls water from the tank to the prefilter. Tube2 pulls water from the prefilter to the pump. Tube3 pushes water from the pump back to the tank. The intake water from tube1 has been biologically filtered by the UG filter. The intake water from tube2 has been mechanically filtered by the prefilter. Thus, the output water from tube3 has been biologically and mechanically filtered. Caution: be sure to monitor the tube connections. There are 5 in the line-up — and 4 of those are potential leak points outside the tank. Two are on the prefilter, and 2 are on the pump. Make sure they’re secure. I keep these parts in a plastic container just in case there’s a leak. However, this precaution is minimal. If I don’t catch the leak in time, the water will overflow onto the counter and floor, draining the tank of water.
Views of the left and right return tubes. The flow is rated at 3.5 gallons per hour, so it’s a trickle. With two pumps, one for each half of the UGF, the rate is approximately 7 gallons per hour. The theory is that this mechanical filter, added to the UG biological filter, will help to sustain the water quality. Also, the extremely slow flow rate may be ideal for opae’ula. Flow rate has been a problem with UG air filters and powerheads for my relatively small tanks. They’re too powerful and the agitation causes salt creep, a persistent problem in my 10-gallon tanks.
One of two AquaClear 1000 Powerheads in my 18-gallon (filled to 10-gallon level) tank. This is the only powerhead I’ve found that’s suitable for my small tanks (largest is 10 gallons). These powerheads are rated “for aquariums up to 10 U.S. gallons.” The critical factor is the flow is adjustable. At full strength, the flow is still too strong. However, at the lowest setting, the flow is perfect. The price is also unbelievable — $8.50 U.S. in Hawaii. Prices may vary elsewhere. Mahalo, Namruso, for your tip! I finally made it down to Petland in Kahala and bought some of these. As you say, they’re perfect for small tanks. I wish I had done it sooner.
Setting it up in the tank was a bit of work, requiring trial and error. I wanted to have the head sitting above the surface to monitor the flow of water. This required some awkward jiggling, but I finally got it to work. Gone are the unsightly air pumps and tubes. Gone is the constant noise. These babies are silent. I also added two of these to the 10-gallon on the kitchen counter. Finally, I replaced the air tube in the 5-gallon Fluval Chi UGF with one of these powerheads. I hope this will reduce or eliminate the salt crusting.
UPDATE 1/7/17 – After 6 months, I’ve given up on the powerheads and returned to the good ole air pumps. The current was just too strong for my small 10-gallon tanks, which are really filled to the 8-to-9 gallon level. I noticed that opae activity had been declining progressively to the point where they were no longer swimming about. As soon as I made the switch, they became more active again.
The powerheads seemed to reduce the salt crusting a bit, but the cost in terms of tank health was too great. The powerheads also had a tendency to slip off their rubber mounts on the tube. This was a danger to the opae that wandered too close. They were sucked into the powerhead and churned into chum. I didn’t always notice the problem until many hours had passed. I tried to stabilize the seating by shoving a short length of plastic tubing over the oval intake and placing the whole back into the uptake tube. This worked for three of the powerheads, but not for the fourth, which kept slipping out of the tube.
I’m setting up a 1-gallon opae’ula tank in a glass jar I found at a thrift shop. This tank is about half done. It shares an air pump with the oblong 1.5-gallon tank that’s partially visible in the background.
Opae’ula are fun to raise. Since they don’t need much space for a simulated natural environment, we can be creative in building tanks. I believe a gallon jar is about the smallest optimal size. At a thrift shop, I found a 1-gallon glass jar (see photo above) with a lid and decided to turn it into an opae’ula tank.
Since there’s no opening for an air line, I raised the lid at one end about a quarter of an inch to insert a line. Since the lid is made of glass and a bit heavy, I added two rubber shims on both sides of the line to prevent the lid from crimping it. I made the shims out of two quarter-inch wide rings cut off from the end of a large plastic hose. Cutting through the ring at one point creates a u-shaped shim that will fit over the bottle edge.
The tank is not quite ready for opae. Thus far, I made a UGF out of a plastic cover (see photo below of a similar cover) and a spare plastic tube, covered it with gravel, inserted an air line into the exhaust tube, and added brackish water from one of my established tanks. I’ll be adding a coral substrate over the gravel next before adding a small colony of opae from the 18-gallon. Continue reading