I use one of those little thermometer tubes that floats in the water. It bothers me sometimes because the suction cup doesn't always want to stick and keep things where I want them! Maybe some member knows a trick for that? But thermos are cheap luckily.
rabbut makes a good point that since you are indeed over there possibly right in the middle of some of our good UK members, you might get to head out into that sunshine and pick up a mature media donation from someone. It could turn a worst case 3 months into a best case 1 week! But often getting a media donation is a bit of a longshot.
On the practical side (sorry if you've already done this) you will need to be thinking about getting a good liquid-reagent based test kit. I and many of the other members use the API Freshwater Master Test Kit and there is also one called the Nutrafin Mini-Master that may be even better or about the same. A good test kit the these minimal tests is really a great thing for beginners and will be used on out into the future.
You'll also need to start looking for the right type of pure household ammonia if you are going to fishless cycle. It needs to not have any dyes or soaps in it. When you shake it, it needs to only make bubbles as if it were water - it should not foam. In UK it is usually found marked as a 9.5% aqueous solution of ammonia in water. The UK folks can recommend some stores/brands (and searches on TFF will find you all this and even pictures of the bottles sometimes!)
So what are the pinned articles going to talk about? What is the nitrogen cycle? Fish give off ammonia from the respiration process going on at their gills. Fish waste, excess fish food and plant debris all get broken down (by some fast-acting heterotrophic bacteria in the water - these are not the beneficial bacteria we are trying to grow in our filters!) into ammonia. So an aquarium quickly has significant ammonia building up and even the biggest aquariums are way too small to dissipate this as mother nature does in the massive size of a natural body of water.
Ammonia burns the gills of fish and causes permanent damage, even in small amounts. Given a little more ammonia and time, the fish will die.
The first type of beneficial bacteria we try to grow in our filter is one that eats ammonia, lets call them the "A-bacs." They eat ammonia and produce nitrite (NO2) as their product. In fact for every part of ammonia they take in, they produce 2.7 parts of nitrite (NO2).
Unfortunately, nitrite (NO2) is also a deadly poison to fish, just like ammonia. Nitrite attaches to the hemoglobin molecules in fish blood and takes up spaces where oxygen should go. As a result, the fish suffocate and either die, or have permanently damaged nervous systems I believe.
Luckily, the second type of beneficial bacteria that grows in our filter is one that eats nitrite (NO2), so lets call them the "N-Bacs." They eat nitrite (NO2) and produce nitrate (NO3) and again, even more nitrate is produced than there were parts of nitrite. The good news is that nitrate (NO3) is not nearly so harmful as either ammonia or nitrite. Nitrate can be left to build up over time without hurting the fish and then is removed when we do a water change. There's some skill to learn about water changes, but many typical aquarists perform them on weekends as a standard part of maintenance.
So Fishless Cycling is a clever process of taking a new tank with new tap water and a new running filter and adding just the right amount of pure ammonia to it that we simulate a nice population of fish. The ammonia and fresh water running through the filter are an irresistable invitation to the "A-Bacs" to attach themselves to the media (special "biomedia") in the filter and begin to form colonies of cells in the form of a "biofilm." Biofilm will naturally form on all surfaces of the tank, but will especially grow in the filter.
Once the "A-Bacs" grow a large enough colony that our tests can detect them producing nitrite (NO2), the "N-Bac" cells will have begun to eat the nitrite and will form colonies somewhat more slowly than the A-Bacs. If you don't have a donation of mature media then the process can seem to take forever. My fishless cycle took six months (twice as long as the worst case because our tank broke at the 3 month point!) Many fishless cycles take between 3 and 6 weeks.
You can start growing live plants during fishless cycling, in fact there is some chance the live plants will bring in some of the beneficial bacteria and possibly provide an "inoculum" (if I've got the word right!) but its nothing like the kickstart of a mature media donation. One down side of starting the plants early is that there is so much ammonia in the fishless cycling tank that you will almost always get a lot of algae on the plants.
On TFF, our working article on fishless cycling is the one by rdd1952. In the Add&Wait method write-up, he covers the process in a way that helps you see the whole picture and know what to do. There are other bits of lore around the edges however and it really helps to keep a careful logbook of your daily test results and notes and to consult frequently with the members here for feedback and guidance. Check out Miss Wiggles article on the overall process of tank setup. Sometimes there are other things that need covering at about the same time as you are trying to absorb all the new info about fishless cycling.
Good luck and hope I'll be seeing how you're doing from time to time,
~~waterdrop~~
