Last year we fabricated and fitted a few sets of steel bands to concrete tanks that we had installed liners in, to reinstate the structural integrity of the tank at full capacity.
Horizontal cracks are fairly stable but vertical cracks can render the tank quite unstable. If you don’t ensure your concrete water tank is structurally sound, as a worse case scenario you could find your tank wall giving way under the pressure of however many tonne of water you had stored in the tank, as you can see from the picture above. The tank liner provides the waterproof seal to stop the water leaking out, but it will not hold the weight of the water should the the tank wall give way.
If you are unsure about the structural integrity of your concrete water tank, fitting steel bands may be the simplest way to give you back your piece-of-mind, and can also potentially avert further movement and cracking of the tank wall in the future.