Re: White Cloud Mountain Minnow Fry.
#9
If you already have an air pump you can fill the spare tank with water from the main tank and start by just running an airstone for oxygenation while you wait for the filter. Most air pumps don't have a speed control as such, so to ensure the airstone isn't too vigorous either us a clamp to reduce the flow a little or tie a loose knot in the airline to achieve the same end.
With the sponge filter attached, there should be no need to reduce the air flow. A sponge filter like that provides good biological filtration once it has cycled, (they are frequently the only filtration in Discus tanks), but is not effective for removing any solid waste so daily syphoning is the way to deal with that. It's vital to do daily partial water changes anyway on fry tanks because there is inevitably excess food to remove and water quality needs to be excellent for proper growth and to reduce the risk of the fry contracting fungal or parasitic infections (they are very prone to Velvet Disease for instance).