¡No Más Verde!

Chris Fifo

I’ve been making a little more of an effort to work on my Spanish this spring. Really! I’ve always said, jokingly of course, I know just enough Spanish to get my face slapped. If only I had the foresight in high school. Unfortunately, I took three years of French. Not so useable in the

I’ve been trying to encourage my son to take some Spanish, but he won’t. With only his senior year left now he thinks it would be a waste of time. Isn’t foreign language a requirement in high school anymore?

No más verde. No more green. No, I haven’t found another creative way of killing my crop; I’m talking about under my benches. I’ve been on a bit of a roll trying to manage some chronic areas of algae in my plug house. Naturally, prevention is key to managing algae and that requires a comprehensive approach.

With our pond being the primary water source, algae pressure can be quite high at times. We’ve improved the aeration to reduce populations and have new filtration equipment ordered that will filter down to 5 microns. (Theoretically … I’m always a skeptic!)

We’re also improving our copper ionization system, which will allow us to more easily maintain our target of 1.5 ppm and use our copper bars down much further (which are quite expensive). This should nearly eliminate algae coming in with our water. But this is a greenhouse—it’s always wet and there will always be green under the benches without regular attention. By regular attention, I mean the use of products: sanitizers, algaecides, oxidizers, etc.

We’ve used a variety of products over the years and our products and procedures have evolved, especially as chemistries have evolved. I generally don’t like to endorse particular products, so I’ll only refer to chemistries and active ingredients (AIs).

We start out clean going into our summer production by power washing each house and then sterilizing with a hydrogen dioxide product. Our tolerance for any green is zero (!). We’ll then “cook” the house for a day—close it up and let the sun bake it to 120F. We feel this will volatilize any chemical or other residues left in the house.

Once clean, we begin a weekly application of a quaternary ammonium (QA) product to the floors. This chemistry has been around for a long time and there are a variety of products. Using a portable injector, we’ll wet the floors with a 0.5% solution and let it dry. This shields us from the green (!) growing back too quickly.

The problem is, it does grow back. We’ve been needing a product with longer residual activity.

Now we’ve discovered what’s known as the fourth generation of QA product. This is supposed to have a four-week residual. This would allow me to grow clean (!) for a much longer period of time. However, I haven’t experienced this overall.

The product rep paid us a visit a few weeks ago and I showed him some of my green. We discussed how the algae broke through the program and how I could foster (!) a more successful management strategy. I know there were weeks the treatment was missed, there were occasions of incomplete coverage and there were times the solution was washed off before it dried. This diminished my control and gave me green.

Now what? I can’t power wash in the spring! That’s when I discovered what’s become my new favorite product.

It’s a granular algaecide and oxidizer. And a strong one at that! The AI contains a peroxyhydrate and it allows me to clean the green like a pro (!). It comes in 50-lb. bags and at a rate of 1 to 2 lbs. per 1,000 sq. ft. for heavy algae or ½ pound for maintenance, it’s fairly cost effective. All I have to do is wet the floors and spread the granules evenly, and a little heavier in the hot spots. Anywhere there’s green, it starts bubbling away as it eats the green off the concrete.

The next day, it washes right off with a hose and I can start my QA treatments again. ¡No más verde!

Hasta la próxima vez amigos. ¡Gracias! GT

Chris Fifo is Technical Services Advisor for Swift Greenhouses, Inc. in Gilman, Iowa.