hello folks me again sorry to hound you with questions, but i have recently installed a new uv filter in my pond, and ever since i have noticed that the two largest comets 6-7 inches long have started swimming backwards and all of the fish 14 in total are spending more and more time at the surface which is great as i can watch them go about there business, they also seam to spend time just floating not moving as if suspended in time is this all down to the new filter?

A UV filter should not effect the fish directly because it does not contact them in any way. If the UV filter kills a lot of suspended algae, then the loss of algae may change the fish behavior. They would tend to be more skittish and not less without the cover of suspended algae.

How warm is it there? Hanging at the surface, gulping, and laying around could just be indicative of higher temperatures and the resultant lower oxygen levels. Adding extra aeration helps with that.

I'm not sure why your fish would be swimming backwards.

Thanks Robyn always enjoy the feedback. I wouldn't say the fish are gulping they are either floating doing nothing or flying around like raving lunatics, when feeding time comes they have become more friendly if anything as soon as i move to the pond they seem to move around looking for food which i'm over the moon with, as far as the temperature goes we've had loads of rain its just warmed up over the past few days and it does look like there sunbathing but i'm going to draw the line at putting cream on there backs lol (what could i use to aerate the pond other that a water fall)

I have a small pump with a fountain head just spitting across my pond for extra aeration. I have a serious algae and ph problem so have to keep up the Oxygen.

Fish may alternate sulking and spazing if they are scared or something is wrong with them. It's hard to pinpoint what that might be. Lots of rain causes problems because it will dilute out the minerals and ions in the pond. Check the pH, hardness, and alkalinity; they may have all gone down.

You can aerate a pond with waterfalls, fountains, spitters, pumps (with outputs directed towards the surface of the water), venturis (fancy squirting returns often used in koi ponds), and air stones (run off an air pump like with aquariums). My 1800 gallon pond has two waterfall systems and an air stone driven by a Luft pump. My 153 gallon has a fountain.

Thanks again folks made my mind up going to add a waterfall system into the pond or a fountain, anything to keep the little fellas happy, only inherited the pond 10 months ago and have already been sucked in feel like some sort of drugy need my daley pond fix lol, will get some pics on when the pond is clearer thanks again folks