Carnivorous Pitcher Plant

Carnivorous Pitcher Plant
one of the first plants in our swim pond

Wednesday, 11 July 2012

string algae

We have a problem - not insurmountable but annoying. When we flushed the filters ( see last entry) this was the first time we had operated the valves. There were a couple of problems (a rock in one valve preventing it turning, and one valve back to front). This resulted in flushing of nutrients back into the pool instead of to waste. We rectified this as quickly as we could but I think a significant amount of nutrient went back into the pool. So instead of decreasing the total nutrient content on the pool we increased it.

Up to that point the pool was looking great as you can see from these two photos . There is very little algae showing on the walls or other surfaces.

After the flushing we left the pumps off since we didn't expect any problem during winter. Then we went away for a couple of weeks. When we came back we saw the hair algae.

So I immediately turned the pumps on again. I also decided that the bottom of the pool should be vacuumed and the sides brushed down to give the filters a chance. But the algae has continued to grow. Of course there would be very little biomass in the filters after first being turned off for 4 days, flushed and then left off for another 2 weeks. So now we are waiting for the biofilm in the filters to re-establish and then to lower the nutrient levels again. The pumps were turned on again 2 weeks ago.

 You can see from this photo that there is algae on the bottom of the pool and on the step. This algae did not want to be swept away- it is firmly attached to the surfaces. By the way the black spots on the bottom are large tadpoles! Even at this time of year we still have tadpoles. However they don"t seem anxious to crawl out of the pool. I don't think they are developing during winter. They are native frogs and definately NOT toads.

And in the next photo you can see the green rocks. you can also see that the water itself is sparkling clear. I don't really mind the appearance of the algae and I'm confident it will clear up as the filters kick in again. Luckily is winter here and algae is not too vigorous. If this happened in summer it might be a different story!

However it is a reminder that this is a living system, and so it is not static. And therein lies the interest!