If you want to run multiple lengths of LED strip from a single controller then you will need to install signal amplifiers to boost your control signal and get over the barrier of trying to push too much current through your LED Strips.

Simple to install -

A simple setup would be - Power supply to 10m 3528 LED Strip to amplifier (with its own power supply connected) to next run of 10m LED Strips - and so on........

These amplifiers will handle up to 12A - so for 12V LED Strips that means you can control

up to 30m of standard 3528 (60 LED/M) strips
up to 15m of Double Density 3528 LED (120 LED/M) Strips
up to 20m of standard 5050 (30 LED/M) strips
up to 10m of Double Density 5050 (60 LED/M) strips

Please note though that this depends on having a suitable power supply for the LED Amplifier, and you should not run more than 2 x 5m of any of these strips from a single point of power. (though if your power supply can handle 4 x 5m power then you can split the power output and run 2 reels from each output)

If in doubt always consult an electrician who specialises in LED lighting.

Specifications :-

5-24V DC Operation
Output - 288W @ 24V DC / 144W @ 12V DC
10cm tails terminating in bare wire for connecting to LED strips
and 10cm tails for connecting to suitable power supply

size of amplifier (including heatshrink seals) 50mm long x 12mm Wide x 6mm High