aqueous solution - How to reduce surface tension of oil?

I would like to create tiny colored drops slowly falling down in a transparent liquid.

The diameter of the droplets must be around 2mm, and their speed must be approximately 0.5 mm / sec.

For that, I need the colored liquid to be slightly more dense than the static liquid.

The easiest setup is to drop water into oil with a syringe.

However, when I drop water from air, the oil surface tension prevents water drops to fall slowly into the oil.

And when I put the needle in the oil, the water accumulates around it and creates huge drops.

I would also like to pump back the water at the bottom to re-inject it later on; so the two liquids must be immiscible.

Is there a simple way to solve this problem?

A better setup would be to increase the oil density so that I can drop it in water (which is cheaper, so much better if I need to scale up my system). I asked another question for that purpose but I could not find any cheap heavy compound miscible with oil.