6.5 months and wakes up at night...?

[annap]

Hi,
DS is 6.5 months/ about 3 weeks ago I weaned him from BF during hte night and we gave him instead water. it seams now that he wakes up for the water!! (we did th esame with older DS and it worked- he stopped waking up) he goes to sleep around 0700-0730, he can either start "complaing" around 1100-1130 pm and we will give him water (in the dark in his bed)' then again at around 0100 am and 0400am/ at 0500 I will take him for BF (when he wakes) since I feel he is already hungry. another fact I feel is important to mention is that he NEVER took the pasi and now after I have "sleep trained" him, when he really cried' I gave him the pasi and he took it and fell asleep!!! I do check that he throwes it him self or I take it out so it does not become a prop. my Q is:
1. how to avoid him waking for the water??? I must "confes" that I slep trained him at the 5 minute round- meaning- every 5 minutes come in and touched him and said mom is here etc... the reason is that he is too heavy and I have a bad back and when I treid the PU/PD it really broke my back and since it wouled with DS 1 I thought to try again!).
2. is it a mistake to strat with pasi now? it really helps him calm down and he takes it (or I do) our after a few monites of sleep.?? (he does not take it during hte day)
Sorry it is too long, guess I am frustrated!!
thanks,
Anna

[annap]

Thank you Jane for your reply... sorry, but what is GS?
his rtn is about:
0600 am wake and BF
0800-0830 sleep for 30-45 mints.
0930: eat fruit (meshed) and if needed- bottle.
1100-1130- sleep for 60 min (more or less).
1230-1300 eat chicken+ veg and if needed- bottle.
1430-1500 sleep for 1 houre (more or less)
1700- eat vegis and BF
1830 bath with older DS
1900 bottle (As much as he wants- usually about 180 ml)
1915-1930 sleep.
night wakings at 11-1130 pm then 0300 am and 0500 I take him to BF. he can also wake soem times around 0100. so we are talking about 3-4 wakings!!
your Q: 5 minutes- he cries or "complains" I come in, touch him and say mom is here, you are only going to sleep etc.. this every 5 mints until he falls asleep. (can go up to 40 minnutes, but since he started to take the pasi- shorter).
what do you think?? 

[annap]

thank you Jane! the A time can be between 2-2.5 hours, I see how he is and call it then...
will take into consideration all that you have said. of course when he cried mom I need U; I go sooner... even the mantra is hard to hear though... hope it gets better, can't wait for that first night to sleep it through!
Anna