Kalphite guardians can be very dangerous for lower levels. They can hit accurately for up to 208 life points in melee, with a chance to poison you if they successfully damage you. The poison does 68 damage per hit. It has been confirmed that using Protect from Melee does not reduce the chance of them inflicting poison against you - it only reduces the damage their attacks deal. Kalphite guardians can be safely ranged or maged from a couple locations (safe spots), however they are fairly strong against ranged attacks. Kalphites are most vulnerable to water spells, making training Magic on them highly effective even at low levels, especially if you take advantage of the safe spots. Despite this, most players still prefer to use melee for training. Keris is also highly effective for training against kalphites along with Guthan's set.
Whilst not the most effective approach, melee is still a popular means of killing these monsters. A good melee weapon such as a godsword or an abyssal whip is recommended, as well as a strength level and attack level of at least 50.
The best way to kill kalphite guardians is to utilise safe spots and fight with magic, preferably water spells (their weakness). By safe-spotting, players can avoid any chance of becoming damaged or poisoned (though they may still become poisoned by a soldier on the way over). A player using their best water spell and a good staff or wand will generally get a much faster kill rate than someone using melee.
Ranged is not recommended, as these monsters have high ranged defence. Nevertheless, if players decide to fight them with ranged, at least 80 Ranged and a strong weapon, such as a crystal bow or black salamander, are musts.
Kalphite guardians have a very slow respawn rate and players should decide if they should kill some more. The only way to solve this is by waiting for them to respawn, which takes a minute or so, or by climbing down to the Queen's chamber, where there are two more kalphite guardians. However, using that spot is HIGHLY dangerous as the Queen can occasionally wander on the other side of the room and begin attacking you, which may result in a very quick death unless players are busy killing her.
The fastest but most expensive way to kill kalphite guardians is use a dwarf multicannon against them, in tandem with the spell Ice barrage. The area unlocked after the Do No Evil quest is good for this. It is a small, open cavern that houses two kalphite guardians and several kalphite soldiers.