Barley straw is a great way to control or prevent algae in lakes and ponds like single-celled algae, aka green water, Blue-Green Algae and filamentous algae, aka blanket weed. Most the time you see fisheries putting a whole bale of barley in to the lake or straw “sausages”, while that is one of the ways to tackle it; it has its down sides. The decomposition of barley straw can feed nutrients to weeds, causing an outbreak and can produce organic waste in a pond. Then there is aquatic “dyeing” that turns the whole lake blue or black, I’m not a fan of that when our lake has gin clear water that I’d like to maintain.
Don’t forget that Barley straw is not effective against higher plants, such as duckweed, watermilfoil, or pondweed. It’s also important to note that eradicating any aspect of the food can have ecological implications.
Bonus: By extracting barley concentrate, it lets you target problem areas directly as well as the entire lake/pond, lets you create and store the concentrate to use when you need it. Unlike bales which can be an eye sore stuffed in the lake, the faff or mess of dealing with bales and also having to make sure they don’t touch the bottom of the lake. Then the cost factor, to buy Barley extract “ready made” can be £45+ per 20Ltr container, this system can produce 650 Ltrs of concentrate for the price (after set up) of 1 Straw bale!
When to use? Starting in the spring and dosing your lake in 10 week cycles all through the growing season. Barley does not kill existing algae, it stops new growth. So its important to start this at the right time of year.
How to extract the concentrate: The process takes 4-7 weeks depending of time of year. Colder months takes 6-7 weeks, longer versus summer at just 4 weeks, so plan accordingly.
– Add a bale of Barley straw in to the IBC.
– Pour in 650 Ltrs of water.
– Switch on the air pump.
– Agitate/mix the straw once a week to make sure it all gets wet.
– You are looking for a “Dark Beer” look to the water and yes it may whiff a bit. When ready, you can decant the concentrate in to 20 Ltr containers. Fill to the brim getting rid of as much air as you can. *Make sure you wear gloves as this stuff is smelly to get off you I am told*
This helps it keep for longer, the average “keep” time is around 2 months.
Dosage: The 1st dose 10Ltrs per acre with aprox average depth of 6ft (more if average depth is deeper) on week 1, then 1Ltr per acer per week for the next 9 weeks and then repeat the cycle. You may want to increase the doses if your water is coloured. You can mix the concentrate with water to help spread it better, 1;1 with water.
How to build all this and list of what you need.
You will need + links:
– Safety Glasses and Gloves.
– Cutting tools eg Angle grinder, hack saw etc.
– 1 x IBC 1,000ltr tank, must be “food grade” can easily be found.
– 1 x solar air pump with 2 air stones LINK. £19. *This one switches back on following day with no need to switch back on.
– Tap adapter for the IBC LINK.
– 16kg dry bale of Barley straw from your local farmer.
– Several 20ltr containers.
– Water, also plan how you will get the water in to the IBC.
– Remove the top locking bars off the IBC so you can remove the plastic tank so you can cut the top off or create a lid so you can bolt the solar air pump to.
– Cut the metal cage down so you can access the lid, be carful of sharp edges.
– Bolt the Solar air pump to the IBC, be sure to point the panel to the sun and fit the air stones in to the tank so they sit at the bottom.
– Break up the straw up in to the IBC.
– Add 650 Ltrs of water.
– switch on the air pump.
Thank you to Gary Bayes for the information and James Bradford for putting me on to Gary.