Who Gives A Fish Forums

I'm hoping someone can offer some advice on this. I recently got my first betta, about two weeks ago, and I'm worried the filter in the tank is too much for him. I've been trying to find ways to baffle it - it's just a basic internal sponge filter that came with the tank.

I've tried a few things so far - tied tights around the output, put a decoration in front - but now I've got a filter sponge around the outlet. This seems to be doing the trick for the current, but I'm concerned it's reduced the flow in the tank too much. The water seems pretty stagnant now. Will this be bad for the fish or the tank?

A picture of the filter would be super helpful, it might give us a better idea of how to baffle it properly.

Here's a picture of my filter with the sponge attached.

CaceyT wrote: ↑Fri May 16, 2025 8:16 am I'm hoping someone can offer some advice on this. I recently got my first betta, about two weeks ago, and I'm worried the filter in the tank is too much for him. I've been trying to find ways to baffle it - it's just a basic internal sponge filter that came with the tank.

I've tried a few things so far - tied tights around the output, put a decoration in front - but now I've got a filter sponge around the outlet. This seems to be doing the trick for the current, but I'm concerned it's reduced the flow in the tank too much. The water seems pretty stagnant now. Will this be bad for the fish or the tank?

One of the key functions of a filter outlet is to create flow and surface agitation, which in turn helps introduce oxygen into the water. By covering the outlet, you've significantly reduced the flow, resulting in minimal surface agitation. This could lead to inadequate oxygen levels in the tank. I'm curious, do you have an air stone in the tank to supplement the filter, or is it just the filter providing circulation?

I'm just using the filter for now. Would adding an air stone help with the oxygen levels in the tank?

I'm worried an air stone would just make the current even stronger, which is the opposite of what I'm trying to achieve with baffling the filter.

I'm curious about why you're trying to baffle the filter outlet in the first place. Was the current it created too much for your betta? I know betta aren't fond of strong currents, being labyrinth fish and all, but if the filter is providing some surface agitation, that's usually a good thing. It introduces oxygen into the water, which is beneficial for your betta.

If the filter outlet is creating a current that's manageable for your betta, and there's still an area of the tank with calmer waters, then you might not need to baffle it at all. Your betta should be able to swim to the surface in the calmer area to breathe air.

However, if the current is indeed too strong, and your betta is having trouble reaching the surface, then baffling the filter outlet might be the way to go. In that case, you might want to consider adding an air stone to ensure there's enough surface agitation and oxygen in the tank.

Betta fish are adapted to live in low oxygen environments, they're air breathers after all. They've evolved to deal with these conditions, so surface agitation isn't a necessity for them.

Raising the outlet to just touch the surface could be a viable solution. Would this allow for enough oxygen exchange while reducing the current in the tank?

CaceyT wrote: ↑Fri May 16, 2025 8:16 am I'm hoping someone can offer some advice on this. I recently got my first betta, about two weeks ago, and I'm worried the filter in the tank is too much for him. I've been trying to find ways to baffle it - it's just a basic internal sponge filter that came with the tank.

I've tried a few things so far - tied tights around the output, put a decoration in front - but now I've got a filter sponge around the outlet. This seems to be doing the trick for the current, but I'm concerned it's reduced the flow in the tank too much. The water seems pretty stagnant now. Will this be bad for the fish or the tank?

It's possible an air stone could create a more gentle current compared to the filter outlet. However, without seeing the unaltered filter outlet and the current it produced before adding the sponge, it's difficult to determine just how much current is being generated. The picture you provided is of the filter after adding the sponge, correct? Do you happen to have a photo of the filter outlet prior to adding the sponge, so we can get a better idea of the original current?

Considering an alternative, you might want to look into a sponge filter.