Posted: 23/04/2012 at 00:23
"To shallow to have a healthy ecosystem without help". Thats a new one on me.
For 30 years I've been dealing with ponds, and the first one I had was approx 50cm by 1m and 30cm deep, oval shaped with crystal clear water. It had 1 fish, 2 frogs and a bullrush, and no filter of any kind. The reason being it was 1980 and mostly in the shade.
Duck weed is a matter of preference, but I like it. When it gets too much, I just scoop it off. For me, it provides shelter for my wildlife and stops the water from turning green, kinda acts like a sunblock, if you like. Green water is generally caused by having a pond in full sun without enough shade. As an result, the water heats up, suspended green aglae think its their birthday, nitrates build up, and..... BAM - problems !!! Ponds, especially ones which are man-made and small, need at least half their water suface in shade but just enough so that plants can photosynthesis and grow. Plenty of oxygenating weed under the water with a balance of marginal and deep plants. The water needs to be kept cool especially in the summer because it heats up more quickly and evaporates more quickly, thus making the water hotter and hotter, therefore carrying less and less oxygen. By fitting a water feature in such a small pond, your going to lose a lot of water to evaporation due to the heat. And less water means a bigger concentration of nasties, more time spent filling it up and an ecosystem that has to spend more time in recovery has it re-adjusts to the imbalance.
IMO a water feature is not your answer. But, if thats what you want, i have seen the kits your looking to buy in B&Q and in plant nurserys.
Can I further add, I have a pond at the allotment which is smaller then yours, converted from an old bath. Half of its contents are plants and the other half is water, I can see to the bottom and its teeming with wildlife. How ? I keep its surface water in shade and out of the sun. My pond has a perfect and healthy ecosystem even though its the size of the average bath !!
I took these the other day.....
The black mass below are tadpoles....