I have been using some of Marcus' excellent compost and have been searching for some slow release fertiliser to add to it.
Someone had recommended Osmocote. Searching Trago Mills I found that I had the choice of two;
Osmocote which claims to last for 6 months (I suspect that it would be less with the constant watering of Bonsai and in the warmer climate of Cornwall)) With a N-P-K of 14 - 5.7- 10.8.
Chempak which claims to last for one year with figures of 18 - 6 - 12 (+MgO)
The Chempak is about 25% dearer but contains micro nutrients which are not mentioned on the Osmocote box.
Anyone with experience of either and/or generally experience of adding fertiliser to composts.
Any advice will be very welcome.