Ornamental Backyard Water Garden Algae Bloom vs Chemicals

There is no water garden that should ever need a chemical to control Algae. If you have a balance of plants and fish you wont commonly get much algae growth as plants can keep the pond in check except during a few weeks each spring plants may be slow to grow and algae can have a short bloom.

More commonly we as water feature owners supply either

1. Too many fish
2. Too few plants
3. Over feeding our fish
4. Some or all of the above.

If you have no fish or plants, you have a fountain or water feature, there you may need chemicals. There are plenty of fish safe algaecides but not all work well. My favorites include the new Algaway 5.4 from ecological laboratories. This fairly potent algaecide is safe for fish and plants. 1 Gallon jug can treat a 2,000-40,000 pond. Smaller ponds it will treat for a year or more, larger ponds it will treat a few treatments. Unless you are growing fish for sport (ie Koi hobbiest) I would focus more on whats causing the alge problem than treating it weekly.

There are plenty of bugs and algae all koi and common goldfish will nibble on on the side of the pond. There is rarely a need to supplement a fish’s natural diet.  You will never see a fish food company tell you fish survive on a natural diet. Most foods tell you to feed 1-4 times daily. If  I didn’t know it I’d say fishfood companies were in the business of marketing fishfood!

Green Clean, a heavy peroxide based chemical (nothing like the low dose in the drugstore) is another common algaecide. It works instantly and does a great job. If your difficulty is on rocks like in a waterfall turn off the pumps for a few minutes, sprinkle the product on the algae and after 5 minutes hit it with some broom bristles, this will knock off the dead algae. Make sure you have an adequate filter to collect dead algae or it will reappear in a few days as the chemical dissapates. Dead Algae is pur nutrients, add sunlight and water and about 5 days aftertreatment a new bloom can occur. A vicious cycle.

Barley straw is a natural substance that has an enzyme that is released as it breaks down. This enzyme retards algae growth. Note liquid barley extract works better than the bundles and a little better than barley pellets.