Hi
Well the first part is would the bricks actually retain the water?? many unglazed types will seep eventually.Second it is very difficult with all those joints to not have a single leak. A nightmare trying to figure out which one is leaking.lol Certainly won't be cheaper than a lined pool that's for sure.
Cement leaches a lot of stuff into the water when new but there are several treatments for it. Just takes time and some extra work. the brick should be no problem.
In my own experience I've never had a cement pool that didn't eventually leak so i ended up using a liner anyway lol. hopefully somebody with experience will chime in here. I'm curious if there is a way to tell if a joint will leak. gary

We had a 30 year old cement lily pond which accidentally got filled with dirt during a remodel a year ago. Just dug it out, and it doesn't leak. of course the digging out was like being on an archeological dig--finding fish and flowers in layers. I secretly tossed pennies and even foreign coins in and the grandchildren did the digging.

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Here's a pic of my pond that is (sealed) brick walled/concrete bottom, but below ground. It's about 10' x 8' x 2.5' deep, plus the small leg. It's around 19 yrs old, and has several large cracks- in the mortar and cracked brick. (I just purchased the home it came with recently and have been trying to fix the cracks myself with hydraulic cement- But it's difficult to locate some of them as was suggested.) I've heard the previous owner had it repaired at least twice and I assume gave up before deciding to sell. Also, I'm in Ohio so temperature differences from seasons are more drastic = more cracks..

I think a great scenerio since you have the materials would be to create an outer brick wall, but keep the inner portion all liner. If I can't repair the cracks well enough and get more leaks after next winter, there will be a liner in the future!

We just installed our first try at a pond using a liner. To build the waterfall, hubby first dug out the hole at 7x10x18inches deep,laid down carpet, then the liner, then started with river rock and began adding cement to the outer rocks and to create the bowl at the top. We have several leaks, non major, and it appears they are between the outer rocks. My question is: Will these fill in with the sediment that runs into the pond following a rain, or will they eventually have to be plugged? We are so new to this!

there is a product called Flex Seal that will take care of any crack. Sold on line or at Lowes.. Get the stuff in cans not the spray

not to seam mouthy but, the question was...Will it hurt my fish & plants, not how to seal the brick & mortar or how to build a pond with those two materials! so does anyone know? will brick hurt the fish & plants???

That would depend on the type of fish and plants. The pH of the water will be increased by the presence of cement. Some fish and plants are relatively tolerant of higher pH, some aren't. It needs a bit of research on what you want to keep. But if the cement is sealed you only have to consider what the pH of the water that you put into the pond is.