I like it. The redmoor is very nice and I like what you have done with the slate. It took me ages to find round pebbles for my river setup, did jot realise home base sold them...
I know what you mean about too much going on. The changes seem to have worked. I would not be surprised if your wood starts floating when you add water though lol. Are you getting any mature media to aid your fishless cycle?
Well, it will once the tank is cycled. I'm currently cycling mine and have gone from constantly fiddling with things to having nothing to do while I wait. Oh well, it'll be worth it in the end!
Glad there are no floaters! (this is bad in fish too!)
I use RO water and make it up in advance and stick a spare heater in it (it is worth having one of these in just in case your primary one fails!)
I am sure the way that you describe will also work (some just use water from the hot tap & mix with the cold) either way you will need to add a chemical water conditioner
Struggling to think of a reason for you! 4 litres in 65 is about 3% so I wouldn't have thought that it would bring the nitrAtes down from 10 to 1.
What I can tell you is that it isn't really anything to worry about at this stage. There's not much point testing nitrAtes until the ammonia and nitrItes are coming back as 0.
When they are both being converted then you will find the nitrAtes will rise sharply - and then it is water changes to reduce them.