"If I moved everything inc fish into the new tank does that guarantee it will be cycled also"...no. The biological system of an aquarium involves various living creatures and several natural processes. This really can get involved, and you can read the cycling articles. But the presence or absences of nitrates does not mean it is or is not cycled. It depends how everything was done. If you moved over filter media without washing it, or substrate, then you would have moved over bacteria but it may or may not be enough. Continue doing what
@Essjay advised on the cycling.
I'm going to let
@Essjay deal with the nitrate level in your tap water, she has explained this elsewhere and better than I can, with her chemistry background. I will move on to mention issues with the fish; this is looking forward to when all the cycling stuff is resolved and completed.
First, the existing fish that will be in this tank. The platy is a livebearer and needs harder water, though this is less critical than it is for mollies. Guppies are also livebearers, but these days their condition is questionable, and they might survive. Not sure what to suggest here, since you have the fish. Definitely do not acquire any new livebearers, they will not be in good shape long-term. Survive is not the same as thrive.
The tetras, danio, loach, rasbora, X-Ray (presumably a tetra like the Pristella?) are fish that shoal. They need a group with several of their own. They have an inherent need in their genetic makeup for this, and we now have clear evidence that even small groups have problems, they need somewhere around ten of each. There is some latitude with numbers depending upon the species, but there is no disputing the fact that without a group, they can get more aggressive and be under stress, which of course leads to other issues like a weakened immune system. The Congo should have 10 or more, no question at all. This fish loves to swim, two males will do races down the tank length. Denying them this is just not fair, when the need is part of their genetics. Neons need 10-12 or more.
Giant Danio...this is another problem waiting to happen. This fish attains 4 inches, but most sources say 5-6 is possible. It must be kept in a group due to its high level of interaction; 8 is considered the minimum number. Their activeness makes them unsuited to any slow or sedate fish, and they are best with medium/larger danio, peaceful barbs, and loaches. Several sources mention their boisterous aggressiveness including fin nipping, and this will more likely be curtailed and confined to "play" if a group of 8 or more are kept in a 4+ foot tank with suitable tankmates. These fish are jumpers, so a tight cover is a must. Up to you to rehome the one, or get another seven.
Loach...what species? Some of these get huger, they have a strong hierarchy and social interaction, and may eat small fish. Need more info on this one.
Rasbora...shoaling too, but what species?
Gourami are sedate, and will not appreciate the activity level of some of the shoaling fish. Another one difficult to suggest. I know what I would do with some of these issues, but they are your fish and I need to help you work things out for the best. But there are some issues that just cannot be skirted around.
I get when I see fish shops with one or two in a tiny tank telling people they make great community fish.
