By Jennifer Ruisch
Green film ruining your day? I’ve been there. What’s that? Not the first time? This has been going on for a while, you say?
You should probably get that checked out.
The benefits of keeping a hydro system far outweigh the risks, if you ask me. But there are some unique challenges that come with keeping an aquatic environment in your home. There’s the ever-present danger of leaks. There’s also the danger of your dog trying to drink out of your flood table. Better Fido-proof your setup.
More likely, you’ve run into more run of the mill problems, like cloudy water, fluctuating Ph levels, or …. drumroll, please…algae.
Algae is a film that you might notice spreading and darkening inside your water container. It is a rootless, ruthless plant that has evolved for millennia to sabotage your hydro setup. It must be eradicated. So we’ve got a little teeny invasive plant that seemingly appears out of thin air. It likes all the same things your plants like. Air, light, water, warmth, and all those nutrients intended for your beloved crop. Algae finds any tiny niche where it can take hold, and once it does, it starts sliming up the place.
First, like other plants, algae creates oxygen during the day, while it photosynthesizes. Then, at night, it uses up the oxygen around it. This means it can suck the oxygen right out of your water. Combat the effects to this by using an air stone or other aeration device to make sure the water is nice and agitated. All the turbulence will help pull oxygen from the air into the water. Also, make sure you’re not keeping your water too warm. High temperatures negatively affect water’s ability to hold oxygen, so you’re not doing yourself too many favors by keeping it really warm. The roots like the stimulation of warm temperatures, but there will come a point where the oxygen levels will start dipping out. I mean–don’t you have trouble breathing when you’re hot and stimulated? Precisely.
I kid, I kid. There are a few things you can do to prevent algae. Make sure you aren’t over fertilizing. This is probably the number one reason people get algae in their flood tables and on other water-logged surfaces and equipment. You only need enough to give your crop a leg up. If there is algae growing in your water, it means there are excess nutrients that aren’t being consumed by your crop. You can probably cut back a bit with no detriment to your plants. Think of it like a diet for your hydro system.
You can get beneficial bacteria that will gobble up the excess nutrients in your water, and hope they will out-compete the algae. A lot of folks are using barley straw rafts in their reservoirs to nip algae in the bud. This is an ancient method that has carried into modern day.
Japanese people that kept decorative koi ponds centuries ago used to use this technique.
Time tested, grower approved. You can save up and get yourself a nice UV filter to kill off fungal spores, bacteria and algae, and sanitize your water. This helpful piece of equipment is proven to cut down on spores and bacteria invading your grow space. A UV filter might be the single most reliable thing you can buy to combat water contaminants.
This brings us to hydrogen peroxide. Does it work? Doesn’t it? I would personally say that it’s useful to your aquatic environs, but don’t put all your eggs in that basket. It’s easy to overdo the H2O2. Getting oxygen in your water is a big job. Don’t expect hydrogen peroxide to shoulder the burden by itself. The easiest way to get your slime carpet under control is to block out the light from wherever it is growing. Line the bases of your plants with landscaping fabric, which won’t trap air, but will block light. No light = no algae. White flood tables are super reflective, so if you can block light out all around the surface, you can cut down on algae growing even in the shadows of your crop. Make sure all the spaces between your baskets or other containers are covered. The best part about this fabric is that it’s relatively inexpensive, and very easy to customize to the dimensions you need. You can reuse it if it’s not too beat up from one grow cycle to the next. Just remember that if you ever have an outbreak of fungus or anything else, toss that ish and get a new roll on.
Last, but not least, when you get in there to remove the green monster, scrub it all off physically – don’t try to rely on some crazy chemical to get the gunk off the surfaces. Just plain old elbow grease will do. And once you get all the gunk out of your table, rinse and repeat. Simply scrubbing the algae off, then running the system like normal will cause the problem to get worse. Since algae has no root system, it simply adheres wherever it can find light and nutrients. Like a desperate, clingy ex, if you unstick it, it will re-stick itself wherever it lands. Once you scrub down the surfaces, you’ve got to start over with new water. Use reverse osmosis water for the purest base, and add nutrients sparingly.
With little effort, and a little investigation, you should be able to get that little green monster under control.