Panasonic 14mm f/2.5 Lumix G lens with cheap R72 filter - Circular IR flare issue?

Bought a cheap 720nm filter off Ebay to try out infrared photography with the 14mm Panasonic lens.

The results were slightly disheartening, see attached images.

Sexy red PL3, now with shades.

El Cheapo Filter.

Macro shot of the filter was taken with my Samsung S4 with a gimmicky magnetic macro lens attachment. It works quite well, it also comes with a fisheye lens and a wide angle attachment for the macro lens. You can see these lenses sitting on top of my laptop in the first picture.

Maysprings. Again.

This was the first shot taken with the IR filter, this is the only photo without flaring (more on that later). Post-processed to remove red tint and increase blueness of the sky.

Canal View

Look at that big stupid circular flare, it wasn't even that sunny today. I guess the flare doesn't look too bad when you shove a canal down it's centre, but it ruined a lot of plant shots.

Frosted Canal

＼(>o<)ノ Insert dirty joke here.

IcanHazMoarFlare?

Flare when lens is directed upwards. (ﾉ｀Д)ﾉ:・’∵:.┻┻

Before Custom WB

This is how the shots look like before applying white balance, I use the camera's custom WB setting but I was indoor for this shot and there was no grass. There is still lens flare even though I was under shade.

After looking through the data for each shot, I found the following:

• Under shade, < f/5, there would be little to no flaring. 
• Under cloudy conditions, f/3.5 had very diminished flaring compared to f/8 which I used for every other shot, I did not shoot any wider than f/3.5.

Will probably make a more comprehensive study of this lens/filter combo's IR behaviour in the future.

Edits:

After reading this post, http://m43photo.blogspot.sg/2012/11/ir-filters.html. I would like to determine how much the filter is to be blamed for the flaring, but that requires money in order to buy better quality filters; I'm poor as shit. Might try a hood over the filter next.

Also, realised that I forgot to shut off IS when using the tripod, DOH! Was wondering why my shots were blurry as crap...