By July, every Kansas pond starts growing something green. A little algae is fine — it’s the start of the food chain. Too much algae kills oxygen, suffocates fish, and turns your pond into a swamp. Here’s how to deal with it the right way.
What Kind of Algae Are You Looking At?
Three main types you’ll see in Kansas ponds.
1. Planktonic Algae (Green Water)
Looks like the whole pond turned pea-green. Tiny floating cells. A small amount is healthy. A heavy bloom blocks sunlight and crashes oxygen overnight.
2. Filamentous Algae (Pond Scum / Moss)
Long stringy mats that float on the surface or grow off the bottom. The stuff that looks like wet hair when you pull it out. Most common Kansas pond problem.
3. Chara (Stonewort)
Looks like submerged underwater plants but it’s actually algae. Crunchy, musky-smelling. Grows on the bottom in clear ponds.
Different algae, different treatments. Match the problem to the fix.
What Causes the Bloom
Algae blooms when you give it three things: sunlight, nutrients, and warm water. Kansas gives you all three by June. Add runoff from fertilized lawns, livestock pasture, or septic — that’s the nutrient load that fires it off.
You can’t change the sun or the temperature. You can change the nutrient load.
Treatments That Actually Work
For Filamentous Algae (The Stringy Stuff)
- Copper-based algaecides — fast knockdown, works in 24–72 hours
- Pond dyes — block sunlight so algae can’t grow as fast
- Mechanical removal — rake it out by hand for small ponds
For Planktonic Algae (Green Water)
- Pond dyes are the first move
- Bacterial treatments — eat the nutrients that feed the algae
- Barley straw — slow-release, works over weeks
- Aeration — keeps oxygen up and disrupts the surface
For Chara
- Copper-based products work but knock it back slower
- Adjust water chemistry — chara loves hard, alkaline water
Don’t Just Treat — Prevent
Kill the bloom, but if you don’t fix the source it comes right back next year.
- Buffer your pond’s edge with grass or plants. Keeps runoff out.
- Don’t fertilize the lawn within 25 feet of the bank. Phosphorus is algae fuel.
- Aerate — moving water doesn’t grow surface scum the way still water does.
- Stock the right number of fish. Overfed fish put nutrients in the water.
What We Carry
We stock pond algaecides, dyes, bacterial treatments, and barley products in our Pond section. Stop in, tell us what your pond looks like, and we’ll point you at what actually works for your situation.
For broader Kansas pond questions — stocking, feeding, aeration — see our Spring Pond Stocking guide.
One More Thing — Don’t Nuke It
Pulling out 100% of the algae at once crashes oxygen and kills fish. Treat in sections — a third to a half of the pond at a time, a week apart. Slow knockdown saves fish.
📚 Related on Mr. Mc’s Market
Stop by Mr. Mc’s Market — Wichita’s Neighborhood Spot
📍 1901 E 21st St N, Wichita, KS 67214
📞 (316) 265-9930
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👉 Got a pond algae problem? Stop in for the right treatment — or call (316) 265-9930.