Hey there. There have been a number of posts on this topic and the problems that come up are pretty much the same. Without substantial support under edges, shelves, sloping sides, etc. the weight of the water will put a bending pressure on a preform that will result in a much shortened life due to cracks. You might try searching a couple of terms that I am too beat from the heat to come up with at the moment.

I would definitely support it somehow. A friend of mine didn't and developed a crack in the second year. She put her new one in the ground. Since you have all patio that's not an option unless you build a raised planter and fill with dirt. that could be quite pretty, surrounded by plants and break up the all hardscape feel.

I've also seen those stacking landscape blocks used. I forget the name but you can find them at most garden/hardware stores. They can be used for retaining walls or just to rim a planting bed. They are colored concrete and interlock so don't need mortar.

Good luck and post a pic when you get it set up! : )

Why not, instead of a preform, use a stock tank. They come in different sizes and support themselves.

I had used a preformed for my fish pond for years. I have moved it a few times and I gotten away with just using sand and blocks to rest the pond on, once just pieces of "recycled" concrete chunks with no troubles or tears at all. Hope that helps!

Why not build a raised planter type structure for your patio out of treated 2x6 & 2x8 and fill it with sand and form the shape you want then add underlayment and liner in the shape you want? If you put ledges around it for sitting,feeding and viewing your fish it would be an asset to your patio and a conversation piece. If you put a fountain in it, it would also be cooling. I have one that I built and really enjoyed until my pine trees became too much of a mess for the pond and I filled it in and it is now a shade garden.

I've done it without any problems but with much smaller preforms. 130 gallons is going to be quite a bit of water weight so you'll have to make sure the unit has some good support.
For several years I had a kidney shaped unit sitting on the concrete pad outside my front door. I had the shelf area propped up with a cinder block and bricks and I had bricks stacked around the outside of it to hid the unit as well as help with support.
The others I have were round units with a fairly flat bottom and 3 small shelves. I had bricks under the shelves and my husband cut some 1x4 pieces to fit snugly on end under the lip of the unit to help with support and then I had bricks surrounding the unit. The kidney shaped one bowed a little bit but the round units have held up the best. I had one of the round ones sitting out in the yard last summer with no support whatsoever with extra plants that I was selling and it did fine.
I think you just need to pick the unit you use carefully and provide some support and you'll be fine.
As already mentioned you can also build a box unit for it or a raised bed and bury it.