Depending on how long you are going to be away would determin how you should best handle the tanks.
If its going to be for a period of 1 week or less then your biggest worry is making sure the tanks are topped off with freshwater. I would not worry with feeding the fish for the week period your gone. Your fish should suffer no ill effects from not having food be introduced to the tank for a period of 1 week or less.
As far as timmers hopefully you have a timmer on yoru lights already. Not sure why you would need a timmer on yoru pump and PH's. Dont you leave them run for 24X7 now? Why would you change this. I have found it best to NOT change anything in how you run the tank prior to leaving. I left for a week once and decided since we was going to be gone to bump the
AC up a bit from 74 to 80. Well my tank overheated and I lost fish due to this. If I had kept the house temp at 74 I bet those fish would still be with me today.
Have top off water in milk jugs or some other easy to access place so whom ever is looking after your tanks can easily add the correct amount to your sump. I like to have a FULL mark on my sump. This way when others look after your tank you can tell them to pour water from these jugs (have them by the tank) until the water level is at this line (show them the mark).
Sometimes I go as far as to hide the food.
If your going to be away on extened period OR you just have to feed the fish then measure out the amount of food to be fed and put it into individual baggies. Mark them with the dates they are to be used and inform the person NO MATER how much they feel the fish needs more only to feed the amount in the bag for that given day.
Hope that helps ya. At least thats what we do.