Your replacement water should be left to stand, preferably overnight, to stabilise the pH as it can change quite a bit when tap water is left to stand, and you don't want that to happen in the tank. So I kill two birds with one stone and put a small aquarium heater in the container of replacement water when leaving it to stand, so that way the water is already the right temperature when I come to use it.
You're right that charcoal is largely unnecessary. There's no real benefit to it most of the time, and the fact that it needs regular replacement makes it an unnecessary expense. I'd recommend some kind of biological media, the more the better when it comes to that. So either ceramic rings, bio balls (not familiar with those myself) or sponge. It's worth having some charcoal media in stock though, for the odd occasion when you may need it, just don't put it in until you need it.
Re: Water test kit, any help understanding the result
Ignore the pet shop, you were doing it right before. 20% weekly is what I've always done. Beware as shops don't always give the best advice. And you're right about the test strips, they are very inaccurate and I wouldn't recommend using them. Another thing worth noting if you didn't already know, is that the pH of tap water tends to change over a period of a few hours when it is left to stand. This is because many water companies artificially alter the pH with dissolved gases, which will evaporate after a while and the water will revert to its true pH. I'm assuming the pH reading you have given is in the tank, it may be worth comparing this with the pH of some fresh tap water, and some tap water which has been left to stand overnight. If you notice a big change, then when you do water changes you will need to prepare a container full of fresh water the day before so the pH can stabilise before you add it to the tank, so you can avoid sudden changes in the pH of the tank.
Re: Water test kit, any help understanding the result
Your ammonia, nitrite and nitrate readings are good, exactly where they should be. Ammonia and nitrite should always be zero, and nitrate below 40. pH and GH really depends on what fish you have, as different species have different requirements. Do you know what the units are for GH? It should say in the instructions somewhere. We normally use German degrees, but with a number as high as 260 it's likely to be some other unit (I'm not even sure if 260 German degrees is possible!) As for the other readings, they're not things that I test for myself so no idea what they mean. What test kit are you using out of interest?
I have bought fish from Pets At Home in the past and I have never had any issues with the fish, they are healthy and their tanks are kept very clean, although I wouldn't necessarily trust their advice. I think to a point it depends on the individual staff member, and the same would go for any shop. If I need advice I come to FK. I haven't bought fish from Pets At Home in a very long time - I tend to favour Maidenhead Aquatics these days, as they have a better range and the staff are generally more knowledgeable. But certainly no problems whatsoever with Pets At Home as far as the fish themselves are concerned, just some questionable advice.
It's certainly normal for Delta Therm and quite possibly for other makes too. I think my old Aquael heater had it too although it was hard to see. It's certainly never caused a problem for me and I can't see it causing a fire (it's underwater!) or tripping your electrics, especially with UK fused plugs. If anything it will blow the fuse in the plug long before it trips your electrics, but even that is unlikely. It's just humidity from the factory which is sealed inside the tube, and not a sign of leakage. It made me a bit nervous the first time I saw it, but I've since learned it's nothing to worry about.
I can highly recommend the Tetra APS300. It's well made, reliable, very quiet and usually costs between ?20-?30. I've had mine just over 4 years and it's never given me any trouble. It has 2 outlets so you can easily run two airstones from it, or you can link the outlets together to run a single airstone. Hoses and all accessories are sold separately. Aquarium airline hose is a standard size, and if the pump is positioned lower than the tank, each hose will need a non-return valve to prevent water from being siphoned out of the tank and into the pump when the pump is switched off.
Is it an Interpet Delta Therm by any chance? In which case yes it is normal. I've owned several of this brand over the years and every single one has had condensation. Others have reported the same. Interpet's website says it is due to humidity in the factory (which of course is then sealed inside the tube) and is perfectly normal, and no cause for concern. Not sure about other brands though.
Hello and happy New Year, and a belated merry Christmas. Hope Santa came for everyone :) I'll hopefully be starting 2017 with a few new fishy arrivals this week - my cherry barb shoal has become somewhat male dominated so I need to give the female population a bit of a boost. I've noticed that too, it's been very quiet lately. I miss the way it used to be :(
Firstly can I ask what size is your tank? And how long has it been set up? Do you have any other fish in there? Your test results look a little odd, in particular a zero reading for NO3 is impossible in a fully cycled tank. So either your readings are incorrect or the tank is not cycled. What test kit are you using? The lack of an ammonia reading suggests that you are using test strips, which are often so inaccurate they are not worth buying. I would recommend the use of a liquid based test kit such as the API Master Test Kit. As far as treatment is concerned, for the fin rot I would recommend Esha 2000, which works very well for bacterial and fungal infections, as well as fin rot and wounds. However if you have already used another medication, you should perform two 40% water changes on consecutive days before using Esha 2000, as the two medications may not be safe to use together. I can't see any white spots in the photo, but it may be they just don't show up very well. If you're sure you've got white spot (often looks like the fish has been sprinkled with salt) then I would recommend Esha Exit. This can safely be used alongside Esha 2000 if necessary.