Check each bag every day to make sure that the paper towel or coffee filter is moist but not wet. If you see a lot of water in the bag, it is probably too much water. If you see there is some dryness, then add just enough water (of the appropriate salt concentration) to make it moist again. Each bag will be a little bit different because the number of germinating seeds will change the amount of water needed. Since you need to check the bags daily to count the seeds that have germinated, it is easy to also check each bag to see if it needs more water. Keep your water concentrations in covered containers so that you don't need to make any more of them. The containers need to be covered so that they don't evaporate and cause the salt concentrations to increase.