You must drip. You can use an IV setup or purchase a drip system from Kent Marine, etc... The reason you drip it slowly is, the solution is roughly at 12 PH
and pouring a gallon in for top off, could decimate your setup. It is best to drip slowly at night when the PH
tends to drop. this in turn keeps the PH
steady as well as, adds calcium to you tank while you sleep... Most tanks do not require dripping Kalk
unless you have a lot of SPS
that is using it up faster than you can replenish with regular water changes. The first thing you need to do is test before you drip anything. You need to know where your level is before you start. If you are not using it up quickly, chances are, you would not need to drip at all.. Be careful.