Re: Modern Water Heaters?.
I'm a big fan of eliminating the glass style heaters from my aquariums completely.
There's been quite a lot of discussion on the matter on who prefers what heater, but I'm a huge fan of BRS Titanium Heaters paired with an Inkbird Controller. BRS sources their heaters from Schego (in Germany), so you might be able to find those in the UK.
I can't speak to their longevity, but if you want something to protect the fish, Finnex makes a titanium heater that has a plastic guard on it: https://www.bulkreefsupply.com/finne...er-finnex.html
Re: Modern Water Heaters?.
After one of my 20+ year old ViaAqua titanium with external analog controller finally quit working I went through a series of newer heaters, some within just a month or two. Some were badly inaccurate and some just quit working all together. After hearing good reviews on Inkbird controllers I decided to buy one and cut the cord on the old ViaAqua and use the tube with the Inkbird. I was so impressed with the Inkbird that I bought 6 more and I use them with both titanium tubes and glass heaters. Time will tell but so far they work flawlessly...