best filter for a fry-only tank

[jade]

My tank's 24 litres, and the fry are only about 2-3 weeks old, free swimming cichlids.

I've seen these filters where the sponge is exposed, blowing bubbles straight up. Do these filters need a separate air pump, or can they work on their own?

To keep the fry safe from the filter and avoid turning my 24 litre tank into a bubble bath, what are my best options, thanks.

[Rampar]

I'd recommend an air pump paired with a foam filter. There are many options out there, but if you want control over the bubbles and flow, consider something like a coarse sponge filter with an easy flow upgrade kit. This way, you can direct the flow and bubbles where you want them, rather than having them blow straight up and turning your tank into a jacuzzi.

[Rampar]

Don't forget the control valves for the pump, they're a must. You'll be able to adjust the airflow and prevent water from getting into the air tube when the power's out. This kit from Amazon has everything you need.

[sSjey]

I've also got one of these filters in my shrimp tank - it's essentially a sponge with an attached pump. I've found it works well, even with the flow turned down in my smaller tank. The product description says it's suitable for tanks up to 120 litres, but the flow is adjustable, so you can tailor it to your needs. I've got mine in a 23-litre tank and it's not too strong even when turned down.

[TwinTankman]

For fry and shrimp, I've found finer porosity sponges work better than coarse ones. My go-to is a Poret foam 3x3x3 inch cube filter paired with a small air pump. Unfortunately, I'm not aware of a UK supplier for Poret, as it's made in Germany. In the US, Dr. Tanner has exclusive rights to sell it. I've had great success with Poret cube filters and Mattenfilters – I've got a bunch of them.