Since kelp tablets are made with fillers you may want to check into filling your own empty capsules with the best quality kelp you can find. I have had very good success with http://www.seaveg.com
That way you can choose if you need a kelp with more sodium or more potassium in it.
Deciding whether to use ACV or lemon juice is a personal choice. I prefer lemon but others seem to do better with the ACV. Take your time and pay close attention to how your body feels as you try the two different acids in your drink. If you are feeling a little nauseous give the lemon juice a try if your adrenals are weak and see if it helps.
Don't worry about the pH test of the drink being acidic in the beginning. Many people have problems with too little acids in their stomachs and benefit from it. In time as you start building your alkaline reserves, your body will start producing a normal amount of stomach acid which will be good when you start upping the amount of limewater to your drink.