interesting idea. I think Algae will be a big problem with all the sunlight. You could grow more plants, like a tropical water lily. But the glass sides will need cleaning weekly.

I have several above ground ponds, for fish I use a small fountain pump set inside a plastic pot full of filter material. I add a pipe to the pump outlet so the water comes out above the surface for aeration.

I have used cattle troughs, large black plastic garden tubs and extra large giant plastic pots for fish ponds with a fountain pump. Sizes from 50 gallons to 300 gallons. The glass would be my main concern. It is a wonderful hobby. I love my fish and tadpole babies and water gardens.

Thank you... I have been looking online for patio ponds and the bigger ones are quite expensive. Then I saw this picture and I have a friend who has an unwanted fish tank that is 6'x3'. My husband can build a wood frame. I love that you can see the fish from the front and not just from up above looking down. But I was wondering what kind of filter I would need, and worried about algae growth... it would not be in direct sunlight, only a couple hours a day. We live in Pennsylvania.

You might try a squeegee for the algae growth that will happen quickly on the inside of the glass. I've seen one pond (can't remember where - might have been here) that had a glass front on a raised pond. Clever, and pretty neat!

Tank is 6'x3'x??. I assume the 6 is the length, is the 3 the width or the depth? And what's the third measurement? What gallon is the tank, do you know?

I wouldn't just place the tank on the patio with nothing under it. There can be uneveness of the patio itself which can warp the frame over time. And also, keep in mind that when it's cold, the cold can transfer from the patio into the tank easier.

A low riser of a solid wood to ensure a level more temp stable friendly base would be helpful. If you notice in the inspiration pic, the tank is raised up on low risers, and likely has a solid base.

Also, unless you plan on draining your tank for the winter, your cabinet will need to be insulated and you will need a water heater for the winter. You may or may not need an insulated face cover for the front of the glass.

Even if you only get a couple hours sunlight a day, that's plenty enough to grow algae. The stuff likes to grow.

The kind of pump/filtration you need... that is going to be an outdoor pond setup, just as if it were any other outdoor pond. What size/capacity you need will depend on how many gallons that tank is.

I have a 1000 litre pond built outside. The front is in direct sunlight a lot of the time sk I put a blavk out cover over the top and bottom in the hottest part of the day. Biggest problem osnt just algae but temperature too. My tank gets to 28 degrees c some days and is far to hot for garden fish. Then you have the problem of cold weather freezing it in the winter. (If it's not deep enough or if the water isnt moving) mine got down to 4 degrees in winter so I installed a heater to keep it topped up that came on for a few hours a night. I would install a bubbler to to add extra oxygen. Lots of plants help with algae and gives fish shelter from the sun. All in all, it's been a very hard project to keep crystal clear. I have a sump tank underneath turning the water over 5 times an hour and it still needed water change of upto 50% every month.

My outdoor tank

Changed gravel to black sand to help with algae growth and put more plants

Yes, you can use very large fishtank as a patio pond. I sometimes travel and write about it, I often met this in different people.