Sorry, no.
"At 1st level, a magus can expend 1 point from his arcane pool as a swift action to grant any weapon he is holding a +1 enhancement bonus for 1 minute. For every four levels beyond 1st, the weapon gains another +1 enhancement bonus, to a maximum of +5 at 17th level. These bonuses can be added to the weapon, stacking with existing weapon enhancement to a maximum of +5. Multiple uses of this ability do not stack with themselves."
The rules for arcane pool specifically state that you cannot use the ability more than once on the same weapon.
Now, at level 9, you will be able to give the weapon a +3 total bonus. This will allow you to make it keen and shocking or flamine burst.
If your asking if you can apply a second applications of Arcane pool to a weapon then the answer is no. The last line of the ability says that when you use arcane pool again while a previous use is still active the initial use ends. However you can enhance the weapon with other spells like keen edge in conjunction with a arcane pool applied shocking or flaming burst at 7th level to get what your looking for.
Keen edge lasts 10 mins per level so while it isn't a all day buff it can potentially last through several combats. If the Magus has one thing its a bunch of ways to improve the weapons he wields. Magic weapon greater last for 1 hour per level so it provides good economy for the cost of a third level slot.
These spells coupled with arcane pool can really shine when a situation offers a tactical advantage by using something other then your primary weapon. Such as Ranged combat when engaging in melee isn't possible or practical or when you have access to a weapon that can bypass the DR of a monster.
Since your weapon is already magical you can add Keen and Shock at the same time with one swift action by spending 1 point from your arcane pool.
But not shocking burst. The OP was trying to get maximum benefit from the increased crit range. At least that was my understanding from the initial post.
Really wow OK my Character is going against and frost Giant I can but keen and flame? but if I want to but flame burst I have to put that on solo? is that right?He can get it... he just needs to be of appropriate level to do so. Can't expect to get ALL your toys at low level now.Since your weapon is already magical you can add Keen and Shock at the same time with one swift action by spending 1 point from your arcane pool.But not shocking burst. The OP was trying to get maximum benefit from the increased crit range. At least that was my understanding from the initial post.
Yes, at level 6, you get a +2 total bonus. Keen is +1. Flaming is +1. Flaming burst is +2. At level 9 you can add a +3 total bonus which would let you put keen and flaming burst.
Another important thing to remember is that your weapons threat range effects any spells you channel through your weapon via spellstrike. Keen is also doubling your touch spell's chance to critical.
my Character is going against and frost Giant I can but keen and flame? but if I want to but flame burst I have to put that on solo? is that right?
If you take a few more moments to clearly type out what you're asking, it will really help the people who are answering you.
The Arcane Pool ability of a level 5 Magus allows him to add +2 worth of enhancement bonus or weapon properties from the list for one minute.
If your weapon is not already magical, you can do any of the following as a swift action by expending 1 point from your arcane pool:
+2 weapon
+1 Flaming weapon
+1 Frost weapon
+1 Shock weapon
+1 Keen weapon
All of those options have a total of +2 worth of enhancement bonus.
If you already have a +1 weapon, you can do any of the following as a swift action by expending 1 point from your arcane pool:
+3 weapon
+1 Flaming Burst weapon
+1 Icy Burst weapon
+1 Shocking Burst weapon
+1 Flaming Frost weapon
+1 Flaming Shock weapon
+1 Frost Shock weapon
+1 Keen Flaming weapon
+1 Keen Frost weapon
+1 Keen Shock weapon
All of those options have a total of +3 worth of enhancement bonus.
At level 9, you have +3 worth of enhancement bonus to spend. You can do all of the above options to a non-magical weapon, or any of the following to a magical weapon:
+1 Keen Flaming Burst weapon
+1 Speed weapon
+1 Shock Icy Burst weapon
+4 weapon
etc.