Fishery management
Do I need an aerator for my lake? A fishery owner's guide
You likely need an aerator if your lake is stocked at a healthy density, is shallow or weedy, suffers algae blooms, or has had low-oxygen scares on warm nights. Aeration adds oxygen and mixes the water — and it's most effective when triggered by real dissolved oxygen readings rather than run blindly.
Aerators aren’t cheap to buy or run, so it’s a fair question: does your lake actually need one? For many UK fisheries the answer is yes — but how you run it matters as much as whether you have one.
What does an aerator actually do?
Two useful things:
- Adds oxygen by increasing the water’s contact with air (through splashing, diffused bubbles, or moving water).
- Mixes the water, breaking down the layering that traps low-oxygen water at depth and moving oxygen down to where fish shelter.
Both directly reduce the risk of the overnight oxygen crash that causes most avoidable fish kills.
Signs your lake probably needs aeration
You’re a strong candidate if one or more of these is true:
- Healthy or high stocking density — more fish means more oxygen demand.
- Shallow water — warms quickly and holds less oxygen.
- Heavy weed or recurring algae blooms — big daily oxygen swings and crash risk when the bloom dies back.
- Sheltered, poorly mixed water — little wind action to add oxygen naturally.
- Past scares — fish gasping at the surface at dawn, or a previous kill.
- High-value stock — the cost of aeration is small next to the cost of losing the fish.
If none of these apply — a large, deep, lightly-stocked, wind-exposed lake — you may get by without one. But you won’t know for sure without measuring.
The mistake: running aerators blindly
Many fisheries either run aerators 24/7 (wasting electricity and wear) or switch them on by gut feel (and sometimes too late). Neither is ideal.
The better approach is demand-based aeration: measure dissolved oxygen continuously, and run the aerator when the water actually needs it.
- When oxygen dips toward your threshold, the aerator comes on — automatically, even at 3am.
- When levels recover, it can switch off again.
- You get a record proving the aerator is doing its job — or a warning if it isn’t.
How monitoring and aeration work together
This is where Lakelytics fits. A solar buoy tracks oxygen around the clock and a smart plug controls your aerator, so it runs exactly when it’s needed and no more. You also get an alert on your phone, so you’re never relying on the automation alone.
Not sure what oxygen level to trigger at? See what is a safe dissolved oxygen level for a fishery, or book a demo and we’ll help you set it up for your lake.
The Lakelytics team
Lakelytics builds 24/7 dissolved oxygen monitoring for UK lakes and fisheries.