Store advisers are hit and miss. Try to avoid asking anyone who is there on a Saturday or under 25 until you know the store better. Best to go in Tuesday morning or something when only the manager and/or full time employees are likely to be there. Also it being quieter at those times means they'll have more time to chat so ask loads of questions. If they love fish and they have time they'll love telling you about how to look after them. Then try another store or this site and see if the advice matches!
Good luck, welcome to fk - I'm new here too and think this site is great.
At some point I'm going to have to redecorate my living room with the big tank in situe. I was planning to cover the tank with a plastic sheet, open all the windows in the house and use water based low-fume paints. Will this be enough ?
Oh. What should the water change be? I was told that when I got them so have been doing that for 2 years!
I use Safe Guard anti stress which is for the tap water. I also added some Nutrafin cycle and King British Green Algae control. I have been adding the algae control since I moved house a year ago as the tank is a little more in the sunlight and was told it was getting green because of that. It's seems to do the trick!
Oh. I think it's 110 pints. The tank size is 76cm long, 30cm deep and 35cm high. This is much bigger than the tank I was advised to get when I got them...I thought the one they pointed out was too small (At least half the size).
What size would you recommend?
Personally I'd change as little water as possible based on the water test readings. Ideally no more than 10% each change but as much as 25% if nessessary. Only change 50% if you are concerned about a contamination. This may mean you have to change the water more often but a small change often is less stressful to the fish.
Algae grows through Nitrates and sunlight, you need to control the nitrates and shade the tank rather than continually pouring algie killer into the tank. Some real plants will help, as will Nitrate-Minus and Easy Balance (Tetra) or similar. Nutrafin cycle is excellent and should be added each week imo.
Good news is that I think that is an 80litre tank (170 pints) which should be ok for those two - but Goldy is the expert on that. My wife was advised a 10L tank for 4 goldfish so its a good idea not to listen to all the advice you get (yup that includes mine too)
Generally if the water quality is less than ideal the fishes immunity is reduced so one fish might get ill while the rest are ok.
A few notes * 50% is too drastic a water change under normal conditions * Did you use aqua-safe or tap-safe on the new water? * 110 pints isn't all that big, I think the experts here will recommend a larger tank just for the fantail on its own.
Red bellied or Pygocentrus nattereri, should be kept as a large even numbered shoal or single fish. Smaller groups tend to pick on the weakest. They grow to about 12" which I think is way too big for the tank you are looking at, even for just one!
Without a filter you are going to have to do lots of water changes, this will be hard as you'll have to get the new water to the same ph and temperature as the water in the tub.
My guess here is that rinsing the new pads in tap water filled them with chlorine and that killed off all the good bacteria in your filter leading to an amonia spike that killed the fish, but hey I'm no expert. Not by a long way.
Do a water test on the tank and the tub. Prep some replacement water for the tub I dont know how often you are going to have to change the water (water tests will tell) but this is going to be a very stressful time for the fish until they are back in their nice big tank.