fishing for roach and hooking into carp and large goldfish

Back a month or so ago i was fishing a small to medium size pond in the middle of a housing estate which is free and hardly anyone fishes there, it's crammed with roach and you can have some really good fun getting a bite a cast, problem is the last couple of times i fished it I've hooked into some half decent carp and large goldfish. I've been using 3lb mainline with a 1.5lb pro micron hooklink, I managed to land the goldfish of about 3lb after a tench like fight but the carp have either snapped my hook link or had me playing them for a ridiculous amount of time 1 carp i played for over 1.5 hours and still lost it when it thrashed over my landing net and slide back into the water. The roach are very finicky biters and using 3lb mainline straight through or thicker means you dont catch many roach but i would like to stop getting snapped up any ideas on what i should do. the one day i fished for about for hours catching roach then got snapped up by three carp on three consecutive casts

why not have ago for the carp but with a heavier bs line,
must have been a big carp to be playing for 1.5hours!

I now it sounds like an exageration but i was listening to the radio and the hourly news broadcast came on twice i just could do anything with it because of the hooklink

I would up the hooklink to 2.5lb b.s. You should still get bites from the roach but would give you a slightly better chance of landing something bigger.

Also, cut down on the feed. Roach will be happy with as little as 5 or 6 maggots/casters every minute or so. (Or every cast, if sooner) Carp generally want more and shouldn't stick around too long if they're not getting fed.

Nicholas do you have two float rods and reels?
I would fish the light set up for the roach until the carp arrive, then put the heavy set up out for the carp.
You could fish 6lb mainline to a 4lb bottom, keep the feed going in and the carp will have it on the heavy set up.
Alternatively you could use Drennan double strength hooklink, but obviously you don't want to exceed your mainline strength with your hooklink.

Just a thought....

That's a good idea dog biscuit, maybe I could fish the lift method on the second rod, what do suggest using for hookbait.
I've tried ledgering and method feeder, on a second rod using differnt baits such as sweetcorn, meat, boilies, worms but not as much as a sniff they seem to be attracted to my constant feed on the float which is either grape sized balls of black supercup, or bread and hemp mixed into a slurry which is ok because i'm fishing close in.
I've also heard rumours that people have caught 6lb chub which doesn't surprise me with all the fry there are to feed on, i've seen anywhere with so many stickle backs present.