Swimming Behaviour

[Charlie06]

Hi all

We have noticed that last night and all today that some of our fish are swimming slowly near the surface of the water, swimming normally. They are not gulping air or anything as they don't break the water, but it seems as if they may be scooping things from the surface. This is the only way I can describe it. They look healthy, feeding well and playing but should we be looking for something else? Is this normal? Has anyone else seen this behaviour? They still swim around the tank, exploring but at odd times in the day they all seem to be doing the same thing at the surface.
I'm not going to waffle on about it now but if anyone has any ideas, could you please let me know.

Cheers

 

[WILDER]

What are your water stats in ammonia,nitrite,nitrate, and ph.
Is there enough rippling of water at the surface of the tank.

 

[Charlie06]

Hi Wilder

All the water levels were fine. We changed a 1/3 of the water and they were swimming all over the tank then, but then we noticed something. As we have the fry in a mesh trap in the large tank, we feed them the powdered food and noticed that the finer food was floating on the surface that had escaped from the net. So we figure that the adult fish are just being greedy and scooping up what they can off the surface. So now we are feeding them a little less as they are having left overs from the fry.
We have also noticed that it seems to be more the pregnant guppy and molly that are staying at the surface. It could just be that they are wanting more food to compensate for the fry they are carrying.
I am certainly no expert yet and am learning something new every day and this is just an observation. We will see.
Thanks for the advice.

Charlie