Question: Please, help me to make out the meaning of water parameters.

[Vivern]

Hello World!
I've just got water tests and here are the results:

80 litres tank, 1 axie.
Ph: 7.25
NH3-NH4: 0.010-0.012
NO3: 40
NO2: 0

I think, NO3 seems to be too high Because there are holes and clefts that are hard to clean? I'm going to change stones to sand, will it help?
Thanks! :)

PS. By the way, my axie (he used to spent several hours out of water some time before) feels and looks good enough. So, thank you all very much for your advices! As you recommended, I decreased water temperature in the tank down to 5-7C and my Lancelot spent about a week in such cold water!

[Neke]

Excuse my ignorance, but what does N03, N02, NH3-NH4 stand for? Ammonia/nitrite/nitrate?

Changing to sand would definitely make it easier to keep the tank clean.

[Abrahm]

Ammonia: NH4+/NH3
Nitrite: NO2
Nitrate: NO3

How often do you do water changes on your aquarium? Do you spot clean regularly to remove visible waste? I can't tell if your tank is done cycling or just starting. You have detectable ammonia, but no nitrite. In the cycling process ammonia appears first, then nitrite and finally nitrate.

If your tank is just beginning to cycle than it is quite important for you to watch the water quality and to do partial water changes when the levels get high. I would watch your water quality and if your ammonia or nitrite levels ever start climbing make sure to perform a partial water change.

Your nitrate is a little high, but not too bad. This is the least dangerous chemical in the cycling process and will always accumulate as the toxic ammonia and nitrite are converted to nitrate. Nitrate also appears in tap water on occasion.

[Vivern]

Neke, that's the main reason why I want to change the ground :)

Abrahm, thanks a lot! :)
I usually change water once in 1-1.5 weeks, I replace about 10 litres every time. Also I try to remove all visible waste, but I'm sure there are several places in my tank that are hard to be cleaned well. Also I have only natural plants, no plastic plants at all.
My tank had been cycled, but when I moved it to the open-air balcony (to place my axie into a cold place) I changed more than 40 litres of water. So, now I think it's not cycled yet.
I'll be keeping watching water params. And when I'll be done with sand, I change gravel to sand.