Yeah, I would leave out the bettas. They need nice warm water
I'm not sure about the goldfish either, but I became an enthusiast when my goldfish got bigger. I only have experience comets, but all single tail goldfish need a bigger tank as adults. They're really best as pond fish. When I was younger I, just like lots of kids, had school fairs with a booth where you would toss a ping pong ball and win a little goldfish. I had no idea when I won any of my 4 little dudes that they could grow to be a foot long! I made a plea to my parents every year for bigger and bigger tanks until I had all four of my fish in a bare bottom 80 gallon tank with very little decoration to take up as little room as possible and they still looked cramped
It was sad
....so I spray painted a hard plastic kiddie pool, put it in the middle of my den, filled it with about 250 gallons of water, made it pretty, and moved my fish over
They're MUCH happier there and my mother's den looks very zen lol. They also felt comfortable enough to spawn when they had enough room, so eventually I moved more goldfish to a friend's big outdoor pond. Sry for rambling lol - miss my goldies! Anyway, this goldfish snob says that 75 gallons may not be big enough for 3-4 goldfish - at least not permanently. They just get too big and create SOOO MUCH WASTE!! You could always do what I do though and get the fish you want and then just give them away to someone with bigger setups when they get too big lol...oorrr use it as an excuse to eventually get a bigger tank
DOJO LOACHES RULE!!!! Just make sure you keep the lid on
I accidentally left mine open last week before I went to bed and one climbed out
So sad to lose those little dudes. Some fish should just be immortal!
Let's see...plants I have in cold water..
Rose sword (I think it's called)
Marble Sword (I think - it's spotty and pretty)
Bacopa Cariolinia (spelling?..Pronunciation?..It's something like that)
Vallisneria - both spiral and Italian I think
Anubias - I've got nana barteri and coffeiola (spelling again?)
Bunch of mosses - java, peacock, flame, x-mas sometimes
I think that's all I've had in my cold water tanks so far.