A few student setup question..?

Hi,

I have a 40 gallon tank which used to house 4 piranhas which sadly died after 3 years due to an unknown disease after weeks of treatment even though my river conditions were perfect.

I now want to setup a neophyte freshwater tank with neons etc but I am unsure about the condition of my container and if it is fit to take fish again?

Should I change the gravel contained by the tank or should I just do a deep verbs on the tank. I still have water contained by the tank from a few months ago but I turned the filters off so im unsure of what to do subsequent? Should I drain the tank, get rid of the gravel and giv it a good verbs then start a new cycle all over again?

Any lend a hand is appreciated

Thanks
Rummynose tetras or Harlequin Rasboras?
If the filter have dried out then it best to just start from chisel.
Give the tank Equipment and gravel a clean, you can use ordinary household bleach at approximately 1 part bleach to 9 parts water this is safe even for plants, a short time ago make sure you rinse everything properly and you should be fine.
Why does my Guppies pick on my...
Only thing you should hold on to, is the tank, the rest has to go; "filter & gravel" Clean beside a very small amount of bleach and rinse like you never rinsed before consent to it air dry for a week. During that time look for what you want and what power filter you need, the kind of gravel and plants for your set up

Good Luck & Take Care
Fish Question. About Betas?
Start all over again or the mysterious disease will afflict your neons. toss the gravel and deep verbs your tank. You should consider a new filter too.
start over again buy new gravel bare tank cause the water is wicked gosh dont you got sense not to be mean cause i be going to would you want to live in nasty stale water also verbs your filter out dont use bleach if u leave any in it it will shoot your fish good luck
Babies still alive..?
Answers:    I would break it down clean it and start over, just to be on the safe side
I also recommend live plants and to carry a good medium for them to grow in use a mixture of clay and gravel, It is an awsome formula for lush plants. It is other sad when your fish perish, especially after that long, be careful when picking your different fish to add them slowly and keep them quarantined before count them when you purchase new ones.
Good luck with your endeavors,
Start all over merely to be safe.
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