A couple of months ago, I was very pleased when a friend remarked how clear my aquaponics fish tank was.  And it was, until about a week later when I saw the first signs of green starting to appear.  A few days later, the water was solid green and my fish were only visible when they surfaced to eat.  I was now in a full scale battle against an algae bloom.

In nature, algae play a very important role.  But in my fish tank, besides being unsightly, they can cause problems such as using up oxygen and causing big changes in the water’s pH.  Neither of these is good for my fish.

There several things I could have done to fight the algae.  The first, of course, was to try to prevent it in the first place.  This particular tank is on my patio and although partially shaded,  it was in full sunlight for a couple of hours a day.  So I put up a beach umbrella for more shade.  I also reduced the amount of food I was feeding the fish.

Another weapon I could use would be an algaecide.  Many people hace used it successfully.  Others, however, end up with no algae and no fish.  I was not willing to take that chance.

Water changes are also recommended, but I was trying to build up the nitrates and nutrients and didn’t want to dilute my tank with a big water change.  I decided against water changes.

My next choice was the install a UV sterilizer.  I had one installed for my saltwater fish tank for which I had paid several hundred dollars.  It had a powerful UV light which was designed not so much to kill algae, which it did, but to kill nasty critters in the water that could make my fish sick.  I didn’t need a light that powerful or expensive for my aquaponics fish tank.

I fired up my computer and logged into Amazon to find a UV clarifier which is was less powerful and less expensive than my pricey salt water sterilizer.  No problem finding one on Amazon that was well within my price range.

A few years ago there was a game people played with the Google search engine.  They tried to find a search term that would return only one result.  It was difficult to find one, but it could be done.  Today, you are hard pressed to find a term that doesn’t pull up a million pages.  Amazon is kind of like that.  Try searching Amazon for a product and see if you can find one they don’t have.

I selected a clarifier that had good reviews and was affordable.  Since I am a Prime member of Amazon (who isn’t), two days later a packages was on my front door steps.  I installed the filter immediately which was easy since it had barbs to fit several tube sizes.  The instructions said it had an easy to read indicator light so you to see that the unit is running, but I really couldn’t tell whether the light was working or not.

After a couple of days, I didn’t see any improvement and because I wasn’t sure the light was working, I informed Amazon that I was returning the unit and printed out a return label.  Amazon has a very liberal return policy.  Then, I selected another UV filter and waited two days for it to arrive.  Like clockwork, it was delivered in two days.  The old unit had been installed for those two days since I decided to leave it hooked up until the new one arrived.

As soon as the new unit arrived, I went to install it.  But as I was about to do so, I noticed my water was starting to clear.  So I left the first filter hooked up, and sure enough on the third day my water showed more improvement.  Same on the fourth, fifth, and sixth days.  By day seven, all the algae was gone.  The filter was working even though I couldn’t tell if the light was on or not.

I kept the second filter for a spare and to use if algae attacks another of my fish tanks.  The moral is that you should take steps to prevent algae in the first place and to be patient after installing something new.  I won a battle against algae, but the war is never over.

I don’t know if the filter I bought is the best or least expensive one you can find, but it worked for me.  If you have algae in any of your aquaponics fish tanks, you may want to consider installing a UV filter.