Water heating update

Just a quick note to record the apparent success of my little heater for the fish water.
My last post detailed the construction of a very simple black polytube heater which seems to be doing the job!!!
After about 2 weeks of operation it looks like the daily addition of just 1 degree of extra heat from the unit has raised the daily minimum temps , in the fish tank, from a low of 6 or 7 to a low of almost 10 degrees now. Still not warm but I think I am finally winning.
This new heat is a bit late for all those poor little catfish but next winter things will be better!!
Yesterday the minimum was 9.6 degrees- but it was a very cold day- it actually snowed quite heavily for about 15 minutes!! At the time Di and I were working in the chook yard making a new house for the new silkies- but that is another story.

I have also added a timer switch to the big pump setup so that the water is only pumped to the growbeds between 8AM and 8PM. The reasoning here is that the growbeds cool down during the night and so will tend to chill the water passing through them.

I have also got the differential switch working and so I don't have to go down twice a day to connect the 12V pump running the water to the heater.
Needless to say all is not quite a bed of roses- the pump draws more power than one 20watt solar panel can comfortably supply and so I have added a second 20watt PV panel.
This problem should be fixed soon as I have a mini maximizer kit which I will build and install when we get back from our little holiday to Hong Kong. This kit adjusts the voltage from the panels to enable a much more efficient conversion of the power from the panel to the load.