i currently have 1 6inch fish in a 35gallon tank...
bare tank with 1400l/Hr overhead filter
and a sponge filter...

amonia and nitite0
nitrate5-10ppm
currently doing 30% water change 2time a week
would this be enough....?

or is it better to upgrade my tank to 55gallon

or just stck to my current setup

With 370ish gph in a 35 gallon tank and only one fish, it sounds like your fish is in heaven.

Your water parameters are staying ideal. The fish could not do better. As long as you can keep the water parameters within those numbers with the amount of work you can/want to do, then you have no worries and have no need to upgrade or change anything.

i want to the fish to grow even faster would giving it additional swiming space encourage it( in Know in other fishes it woks).. or em i good with my current setup

wil a 50 gallon tank be too big for a 6 inch fish( fancy type )

It would not be too big - but I would feed with a definate convention. Always at the same time in the same place with the same signals, so the fish could find the food well before it is swept away by the filters....

I think a 6 inch fish would need the extra gallons at this time to grow "really big" in a quick way. You can certainly do it, though, if you wish. Growth is dictated by a number of factors - water quality is definately one of the most important, but genetics, temperature, food, light duration, etc. all play a part.

if the fish has good genes and good food.. in order to maitain water quality
would a 50 gallon tank require a 30% water change two times a week....?
what would be ideal amount for you...?

more opinions pls.... tnx

I would agree, bigger tanks would most likely be better. More swimming room, and more stable parameters.

Personally, I have had decent growth in my fish. It hasn't been absolutely spectacular, but what I do...

I feed very, very small amounts 3-4 times a day, instead of the slightly larger amount once or twice a day. Most of those will be TetraFin flakes, though one meal a day I usually give tiny bits of apple, or bloodworms, or soaked krill pellets. Something to mix it up a bit, and they love that last meal of the day!

I perform frequent partial water changes, around 20% every other day, or every three days... If I'm not sure if I'm overdoing it or not, I run a quick test strip, but generally, my fish have seemed happy with it. I especially focus on grabbing up anything I can stir up from the gravel, and some days, that can be a surprising amount.

They're tank fish, but I give them indirect sunlight for as long as the sun's up, and have a plantlamp I bought to keep a ti plant alive, that is also shining indirectly towards them, for an almost sunny look. The temperature doesn't get too bad, though, and I keep an eye on it.

I've placed the air bubble wand and the filter in such a way that half of the tank has a gentle circular current, and the fish really seem to enjoy swimming into the wall of bubbles every so often.. My best guess is that it gives them some exercise, and of course I read somewhere that breeders who care only about size used a constant-flow racetrack sort of setup. I prefer to leave part of the tank out of the way and hidden by plants, so they can rest and recuperate from a busy, hungry day.

And of course I keep my tank out of the reach of hungry cats, curious do-gooders, and stray drafts.

It may not work for everyone, and I'm still working on optimizing my system. But so far, so good. Knock on wood and all that...

GreenWater will increase growth rate~