Question
Hello Robyn,

We put in a new small, natural ( no pump) ornamental pond  (rigid liner) last summer and stocked it with two water lilies, one iris and a handful or two of free-floating oxygenating weed. It was beautifully clear, giving us a good view of frog spawn clumps this spring,until a week or so ago when a bright green scum appeared over the surface. I tried an organic  pool 'clearer' and sieving or paper towel wiping the surface but the green comes right back.

We live in SE England and have never had this happen before to any pond. We like to keep a small pond and have it as natural as possible simply to attract wildlife etc.
Hope you can help with the algae problem before the duckweed appears!

Thank you,
Erika  

Answer
The surface algae is common in the spring before the plants get growing well.  I have some in my 1800 gallon pond and don't worry too much about it.  It tends to take over ponds that don't have water movement such as your pond.  I suggest putting in a small fountain or pump to move the water just a little bit.  That will help clear up the algae.  Once the plants are growing, you can turn it off if you want to do so.  Adding good bacteria may help as well as ideas on my site at http://www.fishpondinfo.com/plants/algae2.htm
If duckweed shows up, then the algae won't have enough light, and then you'll have just duckweed.  Adding a little water movement will help control that as well.  Good luck!

Robyn