Update on Creating Backwash With Pump Timer
Previously, in my Creating backwash with pond pump on timer article, I explained how the use of a timer on an "in-pond" pump could help to keep the pump pre-filter cage free from clogging. This was from a suggestion by a fellow ponder.
Since that post in November I have had my pump running on a cheap pin-style timer, to switch off for 15 mins in every hour.
The method works quite well, with the pump filter cage remaining fairly free from matter, although this has been during winter when there is less plant growth, and muck to filter. I will give another update in a few months time when the pond is really active again.
One thing I have noticed from using this idea is that sometimes the water is slightly murky, or a slight film of silt appears on the surface of the water near where my stream and bog area enters the pond. This is due to the bog area draining of water during the 15 minute "off time", when the water stops flowing. Although the bog-area always retains water, the level goes down far enough for some of the fine silt/sediment to be uncovered and get washed into the pond. This results in the murkiness or film on the pond surface.
It is not a major problem though, and only appears to be worse if we have rain as well, as this tends to dislodge the uncovered sediment, and wash it into the pond.
I have not yet made up my mind as to whether I dislike the "drained" appearance of the stream and bog on such a regular interval, and I may dislike this more in the summer. For people without streams this aesthetic may not be a problem. Of course another way of dealing with this would be to reduce the frequency of the pump "off-time" (and hence how often you would see it empty). For example; off for 15 minutes once in every 3 hours, although the benefit of savings on electricity would not be as great then. I will see how it goes this year.
Another minor point is that whenever the pump turns back on it makes quite a loud rude gurgle, as the pipeline re-fills with water and evacuates the air from it. I shall see if anyone makes comments on this when we have garden parties or barbecues!
Watch this space.