How much defense for mineral storage?

I am trying to build up a decent turtle so I can store resources for bigger mines and research projects. I have been using the idea that I can store 25% of the value for that resource. So right now I have on 1 planet:

RL: 9000
LL: 2000
HL: 1143
IC: 383
GC: 618
PT: 123

So 25% of each resource invested in that defense gives me a safe storage of:

Metal: 11.7kk
Crystal: 5.2kk
Deut: 1.2kk

What do you guys think? Am I taking the right approach?

First u shd pick the planet that is spied the least...and try to manage a non-profitability to any tigers around, it means the loses to be grater than gains for the attackers.

As I can see I think u have found a way with the 25 % but u shd consider whos around u and his abilities.

So for the defense: U really could use a lot more LL's and the same amount of IC's as HL....

The best way is to build 100 ll 1 pt and 5 guass on 5 times a week and 20 HL and 20 IC 2 times a week

Hope these ideas help

I'm a firm believer in IC, every 20 you build is the equivalent to 1 large shield dome in shielding capabilities... The higher your shielding the easier to win a battle because it negates a first turn destruction of most of your defenses leading to a costly slug fest for the attacker. Also a HL isn't really all that great. It costs as much as 4 Light Lasers but is barely worth 3 LL in a fight, except of course against rapidfire. Otherwise it looks really nice.