This is the time of year when algae blooms and string algae appears on the rocks of your waterfall. We answer the same question over and over again. How do I get rid of algae?

All algae is not the same. We do not get rid of the different kinds of algae the same way.

Algae bloom is free-floating algae and either requires balancing the system (patience is needed) or a UV system (no patience needed). We’ve written several article about algae bloom. A good one to read is “The Principles of Crystal Clear Water.”

String algae is the algae that hangs from rocks in the waterfall, attaches to plants or simply hangs on the surface of the water. Do not confuse string algae with the soft, jelly-like algae that forms on the sides of the pond. This is good algae. The fish like to eat it and it contains beneficial bacteria.

String algae is tough to get rid of. I like to pull it off and play with it while I talk with customers. It looks like lace when you pull it apart. It has tensile strength. Sometimes pulling it off can be the only way to get rid of it. If you can remove your plants from the pond you can use a quicker method. The Doc’s Prescription String Algae-Away will take care of it quickly. If you can’t remove your plants you simply can’t use this product because it’s a herbicide that kills all plants in the pond.

You clean out the string algae — either by hosing it off, pulling it off or using a herbicide. What’s going to happen just a week or two later? You get it back. Now you need to think of a method of preventing its return. A UV system is useless against string algae since it is not free-flowing. The only preventative method we are aware of is using barley bales. I finally found out how barley bales work thanks to Lyn Miller of Carmel, Indiana who recently purchased a bale from us for a seminar she was doing.

Update 5/19/02: Last year, a brand new product was introduced into the market called AlgaeFix. It kills whatever string and blanket algae is there, then the barley bales help prevent it from coming back.

Basically, barley emits bacteria that thwarts the growth of string algae. That’s why it’s not as effective unless you place it where the pond water will run through it and distribute this bacteria. It will do nothing to any existing algae. It will only help prevent the algae from reproducing. Like any treatment, if you don’t have enough of this chemical in the water, it will not be effective. One barley bale per 1000 gallons is recommended by the manufacturer to do the job for 6-8 months. Don’t expect immediate results. It takes a couple of weeks to get started.