Sponge Filter Stress

I brought home a male betta unexpectedly a few days ago. Right now, he is alone in a 15 gallon column tank with a few giant plants. The flow on the filter that came with the tank was way too strong, so he was admittedly without a filter for a few days. Today I set up a sponge filter. As soon as I turned it on, he started hiding and acting a bit stressed. Usually he is up towards the front of the tank, hanging out and begging for food. Now he is hiding in the back behind plants. I put a tie around the airline tube so there is less airflow, but it still seems to be stressing him out. Does anyone have experience with this?

In the long term, I plan on moving the HOB filter from my shrimp tank into this tank. It has an adjustable flow so it shouldn't be too strong for him. But I need a short term solution.

Edit: Are there any ways to alter HOB filters so the flow won't be as strong? I have a pre-filter sponge in my shrimp tank so the little shrimplets don't get sucked up. When it gets dirty, it definitely affects the flow. I am trying to think of a practical way to decrease the flow on the filter since I think it is the bubbles more than anything that are stressing him out.

 

1. Control valve in the airline.
2. I’ve found the closer the top of the uplift is to the surface, the less disturbance the bubbles make at the top.
3. Do you have an elbow at the top of the uplift? Ie does water and bubbles rise straight up and out, or is there an elbow at the top that attenuated bubble rising speed, and directs flow laterally?

 

Edit: Are there any ways to alter HOB filters so the flow won't be as strong? I have a pre-filter sponge in my shrimp tank so the little shrimplets don't get sucked up. When it gets dirty, it definitely affects the flow. I am trying to think of a practical way to decrease the flow on the filter since I think it is the bubbles more than anything that are stressing him out.

A baffle on the output of the HOB would divert the flow thereby decreasing it. Look up videos on YouTube on how to make one.

 

Bettas don't like strong water flow (currents) in the water. They have long fins and get blown around the place.

I would create a quiet zone in the middle of the tank (since you have a column tank). To do this, make sure the sponge and intake to the filter are at the bottom of the tank and the pipe bring the water up I at the top of the tank - as close to the surface as possible. This will create a gentle flow of water from the top of the tank downwards to the input of the filter and the current will be minimal in the middle of the tank.

Keep the amount of air going into the sponge filter minimal, just enough to see the water flowing upwards through the pipe from the sponge to the surface of the water. You can increase in time if required.

 

A baffle on the output of the HOB would divert the flow thereby decreasing it. Look up videos on YouTube on how to make one.

I will look into that. I think that may be good in general.

He seems fine now with the sponge filter. I think it startled him and I overreacted.