Remember that the x section of a 4 pipe is twice that of a 3 pipe.
Cistern no gutters.
Screwed connections are stronger.
Install standard size mesh gutter covers over the entire gutter that will lead into the cistern.
It is more important that you have unrestricted flow into the cistern.
This is a cistern i made from some pressure treated 2x6 material and a 55 gallon plastic juice drum.
I chose to use 2x6 material because i had it handy but if you choose to u.
K style gutters can be spiked or screwed to the fascia.
This technique is usually only used when there s no fascia board.
A system of gutters and downspouts directs the rainwater collected by the roof to the storage cistern.
Traditionally this involves harvesting the rain from a roof.
Rainwater harvesting is collecting the run off from a structure or other impervious surface in order to store it for later use.
Another method calls for gutters to be held in place by straps fastened to the roof.
Sweep all debris from the roof and gutters leading to the chosen downspout by using a broom.
The cistern typically located underground may be constructed of various materials including cinderblock reinforced concrete or precast concrete fiberglass or steel.
I got the used drum locally for 15 and the wood came from my scrap bin.
Cistern covers are 2 x2 and are cast in the floor.
If you join too many downspouts before they enter the cistern you could have a constriction that would be problematic.