My pride and joy TopBar Hive is good, but I seem to have some husbandary errors which has left the colony lethargic and down.
I fear I opened the hive too frequently overwinter and possibly chilled the brood.
I mixed fondant using sugar. Later to learn it containes an anti-caking agent. The weakened colony has also come under attack from robbing queen wasps, twice they gained entry into the hive that I know of.
Another possibility is that the veroa mite has taken hold.
I shall try a herbal water supply in the form of an infusion of tea derived from tree fungus. Bees themselves will ocasionally drink from the drain off from a variety of mycelium to gain a naturally occuring antibiotic remedy.
My attempts at keeping this first colony is in jeopardy. Much diminished in numbers they are now reduced to just the upper half of three combs. At the end of April I return from holiday and hopefully shall dust over more powdered sugar. Veroa Mite is the culprit and my feeding through winter a mistake which permitted more to flourish on brood that should have been absent at that time of year.