Originally Posted by BigJim
Welcome to AA!
I don't know quite how to say this, but it sounds like you might have a perfect storm for disaster brewing. A little more information about your setup would help a lot.
- What kind and how many fish do you have in your 20g? There aren't any goldfish that can live well in a 20g for very long. Even the little comets can get a foot long.
- What kind of filtration do you have? Goldfish are messy and need a lot of filtration to keep the water quality good.
- Do you test your water quality? If so, what are your ammonia, nitrite, and nitrate levels? If not, I highly recommend getting a good liquid test kit. I recommend the API Freshwater Master. It seems a little expensive, but it lasts forever and is vital for good aquarium health.
Now for your original question: What kind of pump are you running and how is it dying? If the motor is still running, but it's not pumping air, I'd look at your system for excess back pressure.
If the motor dies, I'd check your voltage source. My parents went through a couple routers recently and the problem was traced back to having 135 volts instead of 120 volts coming out of the wall. The power utility company had to fix it.
Cheap pumps could also be the source of your problems. I don't run an air pump on any of my tanks, but there are many people here on AA that do and could recommend a good brand of pump for you.
Hopefully, a "perfect storm for disaster" is not imminent; I'll try to answer your questions.
Tank is 1 year old and in perfect condition. Two fancy fantails, neither of whom is over about 3" long at this point. Filtration is as recommended, water tested weekly, along with 10-20% water change and cleaning/maintenance.
The pumps we're running for the accessory are made by Tetra and rated for 20 gallon tanks.
The motors seem to continue to run, but the air flow gradually slows, then dies, over a 2 to 3 month period.
Could you please explain excess back pressure, along with any ideas to eliminate the problem? Could it be tied to the pump sitting far below water level, and a check valve simply not enough?
Appreciate the help.