Splash Supply Co. Pond Building Seminar — Cleaned Transcript

Speaker: Mark (“the Pond Guy”), owner of Splash Supply Co.

Welcome and Introduction

Welcome to Splash! How many of you have been here before? Okay, and how many are first-timers? Wow, that’s great — that’s over half the room, so I’m super excited.

How did you hear about us? (Audience responses: a show in York, Facebook, radio commercials.) My wife Becky and I did those ads a while back.

My name is Mark. If you ever get an email from me, it’ll say “Mark the Pond Guy.” If you hear me answer the phone, it’s the same thing. I’ve been doing this for about thirty years. My wife Becky is up here — she’s been “playing in the mud” with us for about 20 years. My daughter Campbell is in the back — she’s 14 and has been in the business for about three years now. She’s one of the hardest workers we have on a Saturday morning.

Thirty years ago I started playing in the mud for a living. I went to school for landscape architecture and didn’t really learn anything about ponds there — we started digging ponds for a living and learned as we went. Today, Splash Supply Company is the retail side of our business; we also have a wholesale side where we sell products to other contractors, and I do a lot of consulting — helping other contractors design, build, and sell. We sell up and down the East Coast, from the Hamptons in New York down to Washington, D.C.

Everybody should have a booklet — it has some history about us in it. I’ve had the privilege of traveling around the world to build waterfalls — Mexico, Ireland, Omaha, Epcot Center — but we’ve had most of our fun right here in York County. We build acre-sized lakes and tiny little fountains alike.

My goal today is to share the dumb mistakes we made over the years, so that whether you’re doing this yourself or hiring someone, you don’t repeat them. Our goal is low-maintenance, happy, healthy fish, and crystal-clear water — a relaxing backyard.

Ecosystem Ponds vs. Natural Ponds

The basic ecosystem pond you see in our back garden is a closed system: you dig a hole, put a rubber liner in it, fill it with water, and recirculate that water. We also work on acre-sized farm ponds with a stream flowing in and out — that’s a different animal, and we address that type of pond in a separate seminar (usually in May).

In a closed system, we can control everything, and that’s the goal: we use nature to control nature. We want to get debris out, filter fish waste, and keep the fish happy and the water crystal clear, without a lot of work.

The Evolution of Pond Filtration

This poster (also on pages 4–5 of the booklet) represents 30 years of doing it wrong and improving little by little.

When I first started, we put the pump on the very bottom of the pond. Debris would sink down and clog it, so you’d have to put on scuba gear to unclog it. Debris would build up on the bottom, you’d have to drain the pond constantly, and it was a high-maintenance nightmare. That debris breaks down and emits poisonous gases into the water — so the fish weren’t happy and the water was never crystal clear; it was brown, murky, green — a mess. The rock work was gorgeous, but the water quality was terrible, so a lot of those early ponds got upgraded or just filled back in.

The lesson I share with everyone: 90% of filtering a pond is physical filtration. A pond is a magnet for debris — corn cobs, leaves, pollen, fish waste, twigs — it’s all going to get in there regardless. So how do you get it out?

The Skimmer

In the mid-90s (around ’93–’94), the skimmer came along — just like a swimming pool skimmer, constantly skimming the surface. The pump sits in the bottom of the skimmer instead of the bottom of the pond, so debris gets pulled in before it can sink and decompose.

Our systems are designed to work great and look beautiful — no external pumps or pressure filters sitting out in the open. The first skimming-type filters were made by Aquascape; the founder saw pool skimmers and adapted the idea, using a garbage can and a pool skimmer faceplate to build the first pond skimmer. That’s the single biggest reason our business is as popular as it is — people see a pond with a skimmer and want one.

Skimmer sizing: We carry three sizes:

• Small (Econo) skimmer — flat black plastic lid, smaller mesh basket
• Medium skimmer — fake rock lid, medium basket
• Large skimmer — fake rock lid, big basket

Choose your basket size based on how much debris is around your pond. My personal pond is surrounded by black walnut, cherry, ash, and dogwood trees, so I have the largest basket — I can go weeks or months without emptying it. If you have a lot of debris, go as big as your budget allows.

You also need to size the pump powerful enough to pull debris — like a leaf — all the way into the basket before it sinks. As a rule of thumb:

• Small skimmer: up to about 10′ x 10′ ponds
• Medium skimmer: up to about 20′ x 20′ ponds
• Large skimmer: up to about 30′ x 40′ ponds

Beyond that, we either custom-build a skimmer or use multiple skimmers.

Case study — Leg Up Farm: This nonprofit in Mount Wolf works with kids with disabilities. They originally wanted a fishing dock, but I suggested a half-acre pond with a handicap-accessible entrance where kids could pet the fish instead. We custom-built the skimming system — a dug pit with pumps at the bottom acting as the skimmer — since lining the edge with dozens of standard skimmers would have looked bad. Their maintenance crew just rakes the surface once a month or so.

Installing a Skimmer on an Existing Pond

If you have an existing pond with a rubber liner, adding a skimmer is straightforward (a rigid preformed pond would need to be converted to a rubber liner first):

1. Dig a hole next to the pond, sunk to water level (roughly at the top screw line of the skimmer body).
2. Stretch the liner across the front opening — no wrinkles, no tears.
3. Dry-fit the faceplate over the liner using the included screws.
4. Remove the faceplate (liner still attached), apply a bead of fish-safe black silicone around the frame (not needed across the very top, since water level won’t reach that high).
5. Re-attach the faceplate and tighten the screws evenly, like lug nuts on a tire.
6. Let the silicone cure for about an hour, then cut out the liner opening with a utility knife.

It’s intimidating to cut into a liner you just installed, but it’s simple if you go step by step — the key is no wrinkles and a clean surface.

Placement tip: Site the skimmer as far from the waterfall as possible. If they’re right next to each other you’ll create a dead zone in the pond with poor circulation. You want the waterfall pushing debris across the pond toward the skimmer.

The skimmer door: Our larger skimmers have a door that (1) lets you close off water and access parts in a dry chamber for maintenance, and (2) floats to narrow the intake to about an inch of water instead of six inches — which speeds up flow and pulls debris more efficiently from all corners of the pond.

Everything you need comes in the box, with instructions and videos — and when you buy a kit from us, we usually deliver and unpack it with you. You’re not on your own the way you would be with an online-only retailer.

Planning and Digging: Do This Before You Dig

Do not dig until you’ve bought your pond kit. The process:

1. Take the skimmer and biofalls out of the box and lay them on the grass where they’ll go.
2. Lay out the plumbing between them.
3. Step back — check sightlines from the kitchen window, the patio, any seating areas.
4. Once the layout is right, dig the skimmer hole first (it’s the first thing that goes in the ground — that locks in your water level for everything else).
5. Trench the pipe about six inches deep along the edge of the pond.
6. Place the biofalls (the biological filter/waterfall box) and connect the plumbing.
7. Excavate the pond itself, using all the excavated dirt to build up the berm around the biofalls — this creates the waterfall.

Doing it in this order means dirt only gets moved once, and the pipe (which comes in a fixed length — 25 or 50 feet depending on the kit) gets used efficiently between the skimmer and biofalls.

Our crew can build an 8′ x 11′ pond in a day; most homeowners take a few weekends, months, or longer — and that’s fine, call for help whenever you need it.

Siting the Pond and Waterfall

Rule #1: Start at the kitchen window. Where can you get the most enjoyment from inside the house? (In my own house, it’s my bedroom window — I sleep with the waterfall running, even in winter.) Check sightlines from the kitchen, living room, and any patio or seating areas.

Rule #2: Don’t hide it in the back corner. A wet spot in a far corner under a tree seems like a natural fit, but you’ll never enjoy a pond you can’t see from where you actually spend time. Put it near the patio, where it becomes the center of attention.

If the ideal waterfall spot and the ideal pond spot aren’t the same place, connect them with a stream — a relatively inexpensive way to add a dynamic, multi-waterfall feature.

Grading and dirt: Usually the dig is self-balancing — dirt from the pond becomes the berm for the waterfall, and a bigger pond naturally produces a bigger (proportional) waterfall. Sometimes, though, you have to bring dirt in (sloped yards where the waterfall needs to face the house) or haul dirt out (rocky/hilly sites, or bedrock — like our current Memorial Hospital pond project, where we’re hauling in roughly 30 truckloads of dirt after 30 feet of dirt was cut down to bedrock for the building).

Building above grade: If digging into the ground isn’t an option, you can build a pond up using a retaining wall, as long as there’s enough soil buffer between the pond edge and the wall face to avoid freeze/thaw issues.

Hillside sites: Similar idea — retaining wall, waterfall stepping down the hill, and enough backfill soil between the waterfall and pond edge to keep things level. Water seeks its own level, so the retaining wall needs to hold everything in place.

Trees and Plant Hazards Near Ponds

Because our ponds use a flexible rubber liner, root damage generally isn’t a major concern. A few specific notes:

• River birch: Loves water — I’m convinced these trees can somehow sense water through a liner. I’ve seen roots travel 20 feet and grow up and over a liner to reach water. This just requires an annual maintenance check to trim any roots approaching the liner (won’t harm the tree).
• Sycamore: Very messy/dirty around a pond.
• Silver maple: Fast-growing, powerful root systems — similar to what pushes up sidewalks. Better to avoid planting a pond too close, or work around the root zone.
• Hemlock: The tiny needles get through skimmer basket holes and clog the secondary filter mats — not a dealbreaker, but budget for more frequent cleaning, or size up your skimmer.
• Toxic plants near koi: Not something I worry much about — the list of genuinely problematic plants is short in my experience.

Root protection: Underneath the rubber liner is a heavy-duty nonwoven geotextile underlayment. It’s tough enough to resist a screwdriver jammed straight through it, and it protects the liner from sharp rocks and root growth (tree roots tend to avoid pushing through the layered underlayment/liner/rock rather than fighting through it). We also offer a heavier “rock pad” grade of underlayment for use under large boulders.

Pond Depth and Shelving

Avoid a simple bowl-shaped pond (a design from a 1970s magazine article) — there’s no safe or practical way to get in and out.

First shelf — 8–10 inches deep, dug across the whole pond footprint first.

• Safety: acts like a staircase in and out of the pond, especially important with kids.
• Ideal depth for most marginal plants (we carry around 150 varieties).

Second shelf — 16–20 inches deep.

• Includes dug-out “plant pockets” where the underlayment and liner are pressed down into a hole, so lily pots sit recessed rather than visible on the surface — better looking and easier to keep contained versus letting plants spread freely.

Third shelf — 24–30 inches deep (roughly 75% of ponds, whether DIY or professionally built, land in this range).

• Deep enough for fish to survive winter in this climate — ground temperature keeps the lower two-thirds of the pond from freezing even under 6–8 inches of surface ice.
• Deeper is possible, but beyond about 4 feet you start needing aeration systems and different filtration strategy (as with large lake-style installs). For a typical backyard pond, 2–4 feet is ideal — there’s little benefit to going deeper.

Check local codes: Depth, shelving, and step design generally make these ponds much safer than a swimming pool, but townships vary on rules around ponds vs. pools and fencing requirements — worth a quick call before you dig.

Wildlife

• Herons and bald eagles: Common visitors — we build fish caves into our ponds as shelter/hiding spots. Fish will pack into these caves, especially in winter.
• Mink: Occasional visitors that will hunt fish in the shallow shelves; not much you can do to prevent it.
• Groundhogs: Just drink from the pond — no real damage observed.

Biological Filtration: Why Water Turns Green

Green pond water isn’t the water itself — it’s single-cell algae, which feeds on nitrites.

The nitrogen cycle in a pond:

1. Fish waste and debris create ammonia, which is toxic to fish.
2. Beneficial bacteria (grown on filter mats) consume ammonia and convert it into nitrites.
3. A second type of bacteria (grown on bio-balls) consumes nitrites and converts them into nitrates.
4. Plants absorb the nitrates as nutrients.

Many older or European-style ponds only get through step 2 — enough biological filtration to keep fish healthy, but not enough to clear out nitrites, so the water stays pea-soup green even though the fish are fine. Our approach uses a large biological filter to complete the whole cycle, so you get both healthy fish and clear water — without algaecides or UV sterilizers.

The Biofalls (Biological Filter) Box

• Water enters the back of the box into an open “swirl chamber,” which slows the flow down before it hits the filter media (rather than jetting straight through).
• Water then passes through filter mats (various grades/colors — color doesn’t matter to the bacteria, surface area does), where ammonia-eating bacteria live.
• Then through bio-balls, textured plastic media engineered for maximum surface area (roughly 30x the surface area of an equivalent weight of lava rock, which we used to sell), where nitrite-eating bacteria live.
• The water then flows out over the waterfall, adding oxygen.

Do not clean the biological filter regularly. The brown film that builds up on the filter mats and bio-balls after about a month is the beneficial bacteria doing the cleaning work. Cleaning it kills the bacteria colony and is the most common reason a new pond that looked great initially turns green again a month later. (This is separate from a pressure filter, which combines physical and biological filtration and does need regular cleaning since it’s also catching debris.)

Plants and the Final 10%

Plants absorb the nitrates left over after the bacteria have done their work — starving out string algae rather than killing it with chemicals.

• Different nutrients tend to correspond to different plant traits (leaf shape, color, bloom time), so variety matters: a mix of plants pulls out a wider range of nitrates, leaving less for algae to use, and it looks better too.
• Stagger bloom times (spring through late summer) so nutrients are being absorbed continuously through the season.
• Plant at different depths — lilies deep, iris shallow, marginals on the first shelf — for both filtration and layered visual interest.
• Pitcher plants (sarracenia) pull out unusually specific nutrients that few other plants target.

Summary of the filtration system: ~90% physical filtration (skimmer), ~10% biological filtration and plants (biofalls + plant tables) — after that, it’s just enjoying the pond.

Rock Selection

• Avoid limestone — it affects pH and contributes to algae issues; most locally dug York County rock is also sharp and shaley, which is hard on rubber liners.
• Favor larger, rounded boulders over small stacked stone — big rocks stay put; smaller stacked rock tends to shift as it settles or with wind/frost, leading to liner issues over time.
• Bigger boulders relative to waterfall height create a more natural, “eroded” look.

Practical Considerations

Electrical: Pump cords typically run 15–20 feet. If there’s no outlet within that range, our crews trench a line with conduit, and a licensed electrician (ours or yours) runs the cable and adds an outlet.

Running the pond in winter/year-round: Because the plumbing is buried underground, our systems can run 24/7 year-round, including winter, as long as pump and pipe sizing follow our winter guidelines.

Solar pumps: Not recommended for the flow rates most ponds need — in a real off-grid case (a rainwater harvesting/tilapia project in Africa, nine hours from the nearest power source), a comparable solar setup ran roughly $6,000–7,000 with battery banks, versus a few hundred dollars to run an electrical line in a typical residential setting.

Services Offered

• Free in-store consultations — bring photos and measurements of your space.
• Complete pond kits packed to order (skimmer, biofalls, pump, plumbing, everything needed) — delivered and unpacked on-site.
• Ongoing phone/text support during a DIY build.
• Store staff trained weekly and experienced with troubleshooting.
• Professional installation crew (same core team for close to 15 years) for anything from small backyard ponds to acre-sized lakes.
• Pond service and repairs — email photos of the pond to start a service conversation (contact info in the seminar booklet).

Closing

Thanks for coming — spread the word if you know anyone thinking about building a pond. The display gardens here are meant to give you real examples to reference, not just talk. Grab a booklet, and doughnuts on your way out.