I met Leonardo "Leo" Marin in April 2024, when I picked up one of our overflow calls. He was about to build a koi pond in his backyard in El Paso, Texas, and wanted help choosing equipment. Over the next two weeks we emailed back and forth about everything from filters to koi food.
From an aquarium idea to a backyard pond
Leo first pictured a small indoor aquarium. Then he started watching pond videos with his son, and the idea grew into a koi pond out back.
El Paso doesn't make that easy. Summer heat runs into the triple digits, local pond builders are hard to find, and a lot of building materials aren't made for the desert.
"It was risky because I didn't know what I was getting into. But once I started, I was already in it, so I kept going."
Building it
Leo drew up the design himself and worked with a local contractor to pour the concrete "pool-style" so it would last. The pond stands above ground, 8 feet by 8 feet and 3 feet deep, and holds about 1,100 gallons. The contractor tiled the inside and added underwater lights.
The two glass viewing windows were the hardest part. Thick glass has to stay sealed through El Paso summers, and it took Leo weeks of resealing before they held. When he asked me how thick the glass should be, I didn't know (neither of my ponds had windows at the time), so I suggested he ask the glass company. He went with what a koi pond builder recommended. If you want windows without the custom glass work, take a look at our Pond Portals.
From his kitchen, Leo can watch the koi through those windows. A Buddha statue sits over the spillway, and the lights come on after sunset.
Why koi
For Leo it was always going to be koi. He has long been interested in Japanese history and culture, and what koi stand for there (prosperity, protection, family) means a lot to him and to his wife, who is into holistic living.
"I never thought about goldfish or anything else. It was koi from the start."
He even has a red koi tattooed on his upper arm.
Daily care
"It's like taking care of a baby. Every day I check the water levels, the feeder, the filters. I'm probably OCD about it. But once you see them swimming happily, it's worth it."
Each of his six koi has its own personality. The friendliest, a Sanke, swims over to greet him like a dog would, while the shy ones hang back until feeding time.
What I told Leo before he built
A few things from our emails apply to almost any raised pond:
- Buy more filter than the label says you need. Leo was choosing between two PondMAX sizes, and the smaller one was rated for a bit less water than he planned to have. Filter ratings are maximums and koi grow, so I pointed him to the PF7200UV, which has about twice the capacity.
- Put a valve on the bottom drain line and another on the skimmer line, and add unions around the pump and filter. That way you can take equipment offline without draining the pond, and sooner or later you will need to.
- Put an air stone in each corner the skimmer isn't in. The bubbles keep debris from settling there.
- Keep a net over the pond, at least until the fish settle in. Koi jump, especially when they are new or stressed.
- Build in backup. On my own ponds I run redundant pumps and aeration, and I keep a generator for power outages.
Leo's advice for new pond keepers
Building the pond wasn't easy or cheap, Leo says, but he has no regrets. His advice:
- Expect to put in the time. "At first it feels overwhelming, but once you find your routine, it becomes second nature and rewarding."
- Learn what your pond needs. For Leo, salt and sodium bicarbonate (baking soda) have been a big help in keeping the koi healthy and the water balanced.
What the pond means to him
"It's like another pet. When we traveled recently, I still checked the cameras to make sure everything was okay. It's that important to me."
Leo is already planning a bigger pond for next year.
Leo's pond at a glance
- Location: El Paso, Texas
- Build: raised concrete pond, tiled inside, with two glass viewing windows
- Size: 8 by 8 feet, 3 feet deep
- Volume: about 1,100 gallons
- Fish: six koi
- Construction started: April 2024
Leo's equipment
Leo bought all of this from us for the pond:
- Aquadyne Rhino I bottom drain, 3 inch
- No-Niche Skimmer
- Anjon LandShark external pump, 3,300 GPH
- PondMAX PF7200UV pressure filter with 55-watt UV
- Aquascape Pond Air 4 aeration kit
- Evolution Aqua EvoFeed automatic fish feeder
- Aquascape Smart Pond Thermometer
- Atlantic Water Gardens heavy-duty pond net
- Evolution Aqua Detox inline dechlorinator, 12 inch, for filling and topping off from the hose
- API Pondcare Master Liquid Test Kit
- API KH Carbonate Hardness Test Kit
- Nijikawa Professional sinking pellets, the food he keeps reordering
Plan a pond like Leo's
We rebuilt Leo's pond in our Pond Planner at the same 8-by-8 size, under a pergola on a flagstone patio with palm trees around it.
Here is the same plan from above, with the equipment pad beside the pond and the plumbing drawn in.
Open it in the planner to walk around it in 3D or read the plan in 2D, then press Start my own pond to plan yours.