IBC Tank, Disinfectant Was Stored, Safe?

I've been looking for an IBC tank due to not having masses of space and wanting to hold as much water as possible in a select space, I've found that a IBC tank will fit this role perfectly. I've found a tank that is extremely well priced and happens to be one of the closest ones to me, however it contained disinfectant. Any ideas of how I could go about cleaning it properly for rain water storage? As always, much appreciated.

 

Hello Goku, Is it a 1000l tank? If it's thoroughly emptied out, I should think that any residue diluted in 1000l of water would be harmless to plants....especially disinfectant!

 

Yes, I believe it's a 1000l tank.

 

I've got a couple of them, they stored goodness knows what before, but no ill effects on anything watered from them