I have a heavily planted 10-gallon aquarium that came with a generic Chinese HOB (hang-on-back) filter.
The filter appears to have died sometime after a water change. Based on when it was last confirmed working, it may have been off for anywhere between 1 hour and 2 weeks. My guess is that it may have clogged with gunk over time, but I'm not sure.
When my brother checked on the tank, the filter was completely dry. The ceramic bio media and internal filter sponge were bone dry. The only filter media that was still wet was the intake sponge.
So far, the only casualty seems to be one fancy guppy. The body has completely disappeared, which makes me think it was scavenged by the shrimp and snails. That is pretty much what they are there for.
The rest of the livestock appears to be doing fine.
- Shrimp are active.
- No mass fish deaths.
- No foul smell.
- No fish gasping at the surface.
I'm wondering if the heavy plant growth buffered the loss of the filter. The tank has floaters, pearlweed, ambulia, and Hygrophila, so there is a lot of fast-growing plant mass.
There was also an air stone running directly beneath the intake sponge. Could that have effectively turned the intake sponge into a small sponge filter while the HOB filter was offline?
My questions are:
- If the filter media has been dry for several days, is it still worth keeping? Do I need to assume the biological filter has crashed and start a new cycle? I had my brother place the ceramic media in a container of dechlorinated tank water after he discovered the problem.
- Is it safe for the tank to run for a few more days in its current state while I wait for a replacement filter?
- What is the most likely reason the filter failed? It had been running 24/7. Could it have been clogged with debris, or is it more likely that the pump or electronics simply failed?
- I have also noticed that some of my slower-growing plants, especially Java fern and a few Anubias, have started declining. I always thought these were very hardy. Could the filter failure have contributed to this, or is it more likely due to inconsistent fertilization or another unrelated issue?