The 55 to 65 degrees applies to browns, rainbows, and brooks although brooks would be happier if the water stayed in 50's. Browns are hardier tha then the other two but for best health and success staying between 55 and 65 is your best bet. I have brooks in an approximately 5000 sq. ft. pond right now that do O.K. in the 55 to 65 temp range too.

How do you plan on keeping the water cool enough in summer? Are you going to depend on a cool deeper layer when the pond stratifies? If so, you are gambling and will probably lose due to loss of oxygen in that deeper layer later in the summer. If you were to get by with a cool deep layer that has enough oxygen, feeding would be dicey as you wouldn't be able to see them to feed them. I use floating feed so I can monitor their feeding. You can get by, by not feeding but growth is slower, survival is less, and you can only hold so many pounds of fish vs. fish that are fed pellets.

I run 45 gpms of aerated well water at about 52 degrees 24/7 into my 88 by 59 foot pond in summer that has a steep drop off to 9 feet to keep warming to a minimum. I mix the water column with diffuser in the center on the bottom 24/7 except when air temps climb above 80 during the day. Some use a surface aerator but I prefer the diffuser as I believe it breaks down the wastes produced by my fish and prevents an anoxic layer on the bottom. As soon as temps go below 80 F. in the evening and/or the sun gets low in the sky I turn the compressor back on. This is to prevent too much warming and mixing when air temps are hot.

A liner would be O.K. and should keep weed problems down. However you may have filamentous algae problems if you have too many nutrients from the feed. A way to keep that at bay is not to have too many trout and don't overfeed.

I would feed the fish if you want more than a handful and you want fast healthy growth expecially with a liner.

I put in about 100 trout of about a pound to maybe two ponds every year. They grow to an average of five to 6 pounds plus in 11 months, but I feed them well. I have pics on my website which you will find above.

As far as size of your pond being big enough, the question is not if the pond is big enough but can you keep it cool enough with at least 6 ppms of oxygen? Trout have been, and are being raised in barrels, small circular tanks, raceways only three feet deep etc. My pond is just on the edge of being cool enough or too warm with the 45 gpms of well water I run into it. It could actually be smaller and I would be O.K. But if my pond was much smaller I believe I would have gill irritaion problems from suspended iron that comes out of the well at slightly over 2 ppms. It is reduces to less than 1 ppm in the trout pond as it settles with the inflow.

Any iron in you well water? If so, you need to determine how many PPM's. Much more than 2.5 mg/l and you could have problems especially if your pond is really small.

If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.