Finding just the right balance

Kelsie Diehl, 25, kneels beside bibb lettuce she's growing inside her aquaponic greenhouse on Del Ray Farm in Strasburg. The recent Virginia Tech graduate uses fish for fertilization and grows the plants in water. Rich Cooley/Daily

STRASBURG — After three years of trial-and-error, Kelsie Diehl will sell her first batch of goods from her Del Ray Aquaponics Farm LLC business at Strasburg’s Mayfest this weekend.

Before arriving at this point, Diehl, 25, has had to work through three separate jobs and has experienced quite a few false starts and glitches from within her elaborately constructed greenhouse.

“I love being down here,” she said, “The problem solving is fun. It’s unfortunate when you’re wrong, but it’s a lot of fun … especially when you’re successful.”

The first goods that Diehl is looking to sell are tilapia fish and possibly 80 heads of bibb lettuce.

And Diehl seemed especially excited about the lettuce heads, which were planted during the early March snowstorms and are now beginning to populate the greenhouse beds.

Kelsie Diehl, 25, looks over a group of Bibb lettuce seedlings that are a few days old that she's growing inside on Del Ray Farm in Strasburg. The recent Virginia Tech graduate has a greenhouse with an aquaponics system that uses fish for fertilization and grows the plants in water for a quicker and natural growth production compared to traditional garden planting. Rich Cooley/Daily

“It took a while, because my nutrients weren’t right,” Diehl explained. “Once I got them going, basically it was adding the phosphates and a little potassium, then they just shot up.”

True to the farm’s aquaponic name, the lettuce is grown through a system of connected fish tanks and aqua-based Styrofoam plant beds. Through this system, the fish and the plants exchange essential nutrients like nitrate, oxygen and phosphate.

From initial lettuce plantings in March, Diehl said that she has been constantly tinkering with methods to improve this system of nutrient balance.

“I was experimenting with nutrient levels, how many fish I needed … to raise this many heads of lettuce,” Diehl said, noting that the beds at Del Ray have the capacity to grow 1,100 heads that can each weigh up to 1 pound or more.

Diehl noted that it takes the lettuce about four weeks to become fully grown, but she prepares for a six-week window.

This growth rate is significantly quicker than more weather-dependent traditional vegetable gardening, which Diehl said can take up to 60 days.

Of course, the kicker is that Diehl’s lettuce can be grown on a year-round basis from this carefully controlled symbiotic environment.

Diehl explained, “If you don’t have enough lettuce, then your nitrates get too high … the fish don’t like high nitrates.”

She added, “If the fish aren’t eating as much, then your nitrates get low, so you somehow have to feed more or produce less lettuce.”

Part of balancing this equation is monitoring the temperatures of each individual fish tank through a custom-built boiler system.

In discussing the tilapia tanks, Diehl noted, “You can see that 72.5 [degrees] is where it’s set at, but if it goes over, I’m OK with that.”

The trick with the tilapia, Diehl said, is making sure the water temperature stays above that 72-degree threshold and does not get too cold. “They quit eating at like 68 [degrees].”

This logic is even more true for the catfish Diehl is planning on raising within the next year. Her first attempt at raising them last year ran afoul, partly due to temperature.

“I filled all of the tanks with [700] catfish and every single one of them died,” Diehl said, noting the loss cost her about $500.

“One of the things that killed them was that the water was too cold. 65 [degrees], who knew, was too cold,” Diehl added. “Nothing I’ve ever read has said that.”

She added that the small catfish also suffered from diseases and a parasite that they carried into the environment at Del Ray.

For this next batch of catfish, she said, “I’m hoping that maybe I can keep [the temperature] down at 68 [degrees].”

While Diehl said she now feels she has a solid grasp on the operation, she won’t allow herself to become complacent.

“Every time you think, ‘yes, everything is working and doing just fine’ then something happens,” Diehl said. “So I kind of just always, you know, look around for problems almost every morning and every evening.”

Diehl said she is excited to finally see a return on her extensive investments.

“I’ve had a lot of different people help me here, but I’ve done a lot of it myself,” she said. “To finally have lettuce is like a miracle, I swear.”

Moving forward, Diehl has a bevy of ideas to expand and build upon what she has established at Del Ray. Part of her ever-growing list includes planting tomatoes, possibly experimenting with microgreens and setting up a small shop to sell her products.

“This is the ideal life,” Diehl said. “I don’t think I’ll ever get bored with it. There’s always something that can be improved on, something that I can do better.”

Contact staff writer Kevin Green at 540-465-5137 ext. 155, or kgreen@nvdaily.com