A couple years ago, my wife and I were in a good place financially, and happened upon an estate sale for a mid-century A-frame home on a few acres. Among other notable features, the house came with an INDOOR POOL! Its dimensions were 10’x25′, 4′ deep in the shallow end, and 8′ deep in the deep end. We assumed the risks associated with an as-is home sale, and ended up the proud owners. Here’s where things get interesting.

We closed on the new house at the end of July/beginning of August, and then had to spend a month or so moving from and selling our previous home. There weren’t any major hurdles or roadblocks, just some physical effort required. So sometime in September we started asking around for specialists to bring our indoor pool up to snuff. We quickly learned that at least as far as the pool was concerned, we’d taken a risk, and didn’t get the expected return on investment.

Only one company would even look at the pool, because of its age, and I assume some sort of liability concerns. The gentleman who did show up had to borrow my fishing waders to get in and evaluate the plumbing. The end result was a conclusion that the water lines embedded in 3 feet or concrete were shot – as in swiss cheese. His company, however, wasn’t interested in even quoting the required work. It was just too much, and there was no telling what else we’d run into.

Initial Triage Attempt

So in late September, we rented a trash pump locally, and emptied the pool. No sense in keeping water in it if it wasn’t swimmable, after all. The pool rested fallow through the holidays and the end of the year. Fast forward to New Years Day, 2022, we had been experiencing very wet weather, and I went out to the pool room for some reason, and noticed water seeping in around the bottom seem, and sheeting down into the deep end of the pool. At this point, we’d been considering building a wooden deck over the pool, so we could have additional gathering space. Now with the pool taking on water, would we need to install a sump pump? Things were getting weird.

By April, the pool had filled up to 3′ below capacity. As it turns out, we have a relatively high water table, and groundwater infiltrates the pool like a sieve. The humidity became a concern, so we turned on the ventilation fan to mange it. But what to do…

An Idea

Over the next several months, I had the idea that, if the pool was going to fill in with groundwater anyway, why not put fish in it? I started suggesting this in jest to my wife at first, but after awhile, it didn’t seem such a bad idea, all things considered.

Something I should mention at this point is that I have kept aquariums full of fish, ranging from cold water goldfish to full on coral reef aquariums since I was 14 years old. So I know a little bit about keeping fish alive and flourishing. I once had a pet piranha that lived 11 years…

So I started doing some research. I knew that goldfish and koi would love the space available, but I had other ideas in mind – bass and bluegill. It turns out, very few people post online about a 10,000 gallon “pond” and whether its suitable for gamefish; but there also wasn’t any information flat out telling me I was crazy. So I had my plan. And if things didn’t work out, I had a plan B. My sister-in-law and her husband had just bought some acreage with a 1 acre pond that I could transfer any remaining fish to if the pool was untenable.

Preparation for Fish

In September of 2022, we drained and cleaned the pool once again, banking on groundwater refilling the pool. I asked a few friends to save their cut Christmas trees for structure and tossed them in the deep end. By February, there was some water, but nowhere near enough to support a flourishing colony of the kinds of fish I was intending on adding. Would this be a bust, too?

Thankfully, by April, the pool was roughly filled to where it had been the year before. It was time. We have a fish farm truck out of Arkansas that comes several times a spring to a local store to provide a stocking source for people with farm ponds. About a week before, I added some pond formulated bacteria to the pool, then kept another bottle on hand for adding along with the fish.

Adding the Fish

Sadly, I don’t have any pics of the bags or videos of adding the fish the day we got them. I just didn’t have the fore thought that I’d be blogging about it a year later. Initial numbers were 6 largemouth bass and 30 bluegill.

By the end of May, I’d decided I wanted to build up the population of bluegill to increase the odds that they will breed and provide a more natural food source to the largemouth bass. By this time, I was down to 4 largemouths, and pretty close to 25 or so bluegills. So when the truck came again, I obtained 50 more bluegill.

Adding More Fish

Up to this point I’d been feeding all the fish gamefish pellets, and they were more than happy to consume – and growing quickly. To give the new bluegill fish a fighting chance to find cover in the Christmas trees, I threw a handful of pellets in, distracting the bass; however as soon as the new bluegills hit the water, disoriented from their travels, the bass saw opportunity. Did I mention they had grown quickly? Previously 4-6 inch bass were now 8-12 inches. I estimate at least 25 of the 50 new bluegill were immediately food.

Over the course of the past year, the 4 bass have continued to grow, all solidly 12-16 inches in length, and there are some huge bluegills as well. I estimate the bluegill populate to be at least 30 at this point, which I hope is enough. Here are a few pics:

Here are the bass, schooled up.

The clump of Christmas trees for cover.

The Christmas trees, and a wider shot of the deep end.

In the last photo, you can see my aerator, rated for 10,000 gallons. The stones were originally closer to the middle, but don’t weigh enough to stay in place. As such, the air lines have coiled up over time, but the fish don’t seem to be in distress.

For lighting, I turned to the hydroponic industry, and am experimenting with a 340W LED fixture (3000W equivalent), and hope to add 2 more on a timer system to see if I can sustain any aquatic vegetation.

What’s Next

We need to have an electrician come in and add a circuit(s) for the lighting. I have one more Christmas tree from 2023 to add to the shallow end for fry (baby fish) cover, in case the bluegills breed successfully. I need to come up with a way to weigh down the air stones so the aeration can be closer to the deep end.

Conclusion

While the indoor pond doesn’t look the prettiest right now, I have been surprised with just how quickly these fish grew. There are eating size bluegill – they call them “panfish” for a reason – that I sometimes mistake for the bass. The bass are all around 1 lb and 12-16 inches in length. Time will tell how large the bass might get, and if the bluegill will breed in the pool, but so far I’m at a point where I just need to focus on aesthetics, and consider how I may add some small catfish without drawing the attention of the bass. Both species are thick and healthy, so I’m calling year one a success!

Do you have a farm pond? Koi or goldfish? Or have you, like me, turned a swimming pool – weather indoor or outdoor – into a life sustaining pond? Comment below!