Soda bottle trick lost surface agitation

[JerryO]

So I had the typical problem of my HOB filter being a little too powerful and creating a stronger current than I wanted so I went to the soda bottle trick and it worked great. Now the problem I am having is since I lost some surface agitation there is an rainbow oil like film on the top of the water. It is not thick and skin like like a protein film is, it looks more like a very thin oil (most likely fatty acids from the food).

Would an airstone help get things moving and break it up?

Since I have sand substrate would I need a suction cup type of air wand so it does not kick up the sand and have it end up in the filter?

 

[dkpate]

I had the same thing on my betta tanks until I put a filter in there. When I had too much flow, I got some plastic craft mesh from Walmart and cut it to fit in front of the flow, therefore reducing it. I tied it around the back with fishing line. For a temporary fix, you can run a paper towel over the surface.
As for the air stone, my favorite one is my ceramic one that I got at PetSmart. It's about 2 inches long, white, and it has a suction cup to hang it on the side of the tank. It is my guppy and loaches playground LOL.

 

[BigJim]

There are surface skimmer attachments for HOB filters.

 

[toddnbecka]

I run airlines in all my tanks for the same reason, and most of them have plenty of surface agitation. I don't use airstones, though, they clog up and reduce the airflow volume, as well as putting more pressure on the pump diaphragms. I use the narrow plastic tube that came along with my UG filters and a suction cup to hold the airlines in position in the tanks.