The OP seems to have missed his first chance to recharge the new batts as soon as he got them home and get his "baseline SG" as the target SG for future recharges to True Full.
The new batts would not be at True Full after being on the shelf. They need to be charged right up and even equalizing would be a good move when getting them home.
Doing that now will likely make them spill some water, but it still needs doing. With the added water, the SG will not be quite correct as the baseline, so have to wait till the next cycle or two and then get to True Full for a good baseline SG.
How can you tell if you are at True Full if you don't know the SG for that? you ask. One way is with an ammeter. When amps stop flowing after tapering to zero, that is full. There is SG lag so you have to wait till the battery cools down to get the baseline SG.
Otherwise just do an equalize after the next recharge and take the SG and then see the SG after the equalize after that one. If it is higher, see the next one. Eventually, you will know how high the SG can get.
If you do that on the first recharge when getting home and do not then add water to screw up the SG, then it is easier--but too late for that. Doesn't matter for now--but it does matter if you don't get them to True Full ASAP so the sulphation they have now does not harden.
