I noticed that the stainless steel tank always has a bigger capacity compared to the fiberglass or polytank. Which is better between the two? In terms of longevity and maintenance.

Actually is depend on which area you placing it, direct on sun SS will be much longer lasting... if located on a shelter-in-place polytank will be as good as stainless steel tank.

Opps. My bad. I see few neighbours use stainless steel tanks for capacity above 1000l. For poly, usually 300l

One of my neighbours made this system with the SS tank. Not sure if poly have or not the inlets for it.

The 1125l SS tank is curved at the top and bottom has 2 inlets at the top, and 3 inlets at the bottom.

The very bottom of the curve inlet is used to drain the air karat
The other two bottom inlets slightly higher used for water in and water out

He placed two floatation switches/balls in the tank. One halfway, one at the top.
Water comes in from below.
When the water pressure is low, the water fill the tank up to the first ball. When the ball closes, the water will travel up to the second inlet. When the water pressure is higher at night, the water travels up and fills the whole tank.

Can do this setup with poly tank?

Where I stay, water pressure is quite low. Got worse since more shops built on the main road.

If I open the main tap at the meter, put hose and raise hose above 5 foot, water does not flow. Sometimes only air in pipe and water does not go to tank. Need to bleed at main pipe remove air then water will go in. It used to be that the water pressure is high enough that it can fill the top tank at night. Now very rare.,some neighbours resort to opening the tap at 3 am just to send more water to tank

And as mention SS way longer lasting(around 60-100 years) than polytank(20-30 years) depend on Malaysia weather and material quality.

Ok, true asked some dealers before they mentioned Taiwan/China and local made. Only difference are on quality material.

your roof can sustain the weight of 2 tanks ?

how heavy is 450L of water filled up ?

thanks .

how to measure the concrete slab that can sustain the weight?

my concrete open air ..roof water fall down to the concrete ..after few years ..water leak inside my living room ...
saw small holes on the concrete ...that raining water fall on it..

thanks ...

yes ..after long time the rain water drop into same place ..slowly concrete become holes and crack line ..thus water leak ..

ya...that's why tile for that particular area only ...

what method to apply can last longer to prevent the leak?

thanks ...

that's the only way ...

hi guys, i currently have a poly tank on my roof to supply water to the toilets, however with recent water disruption i would also like to add an additional SS tank at the point of entry to supply water to the kitchen as well. Should this be done? or should i just change to poly tank to a higher capacity SS tank and pull a pipe to supply to the kitchen?

thanks