First question is which 2 part dosing kits do you use?

I have a feeling that my levels will be getting ate up pretty quick soon and want to start 2 part dosing so i would like a little bit of information first.

currently after a water change (or right before i am due for one 2 weeks later) my alk is at a solid 7 in my main tank using tropic marin test kit. i think this is a bit low. my calcium is usually 450 after a water change and 375 right before i am due for one. and my mag is usually 1350 after a water change and 1200 before i am due for one.

Then the past 2 weeks i have added 2 sps mini colonies, 1 frag of sps. and over 20 acans from a few polyps per frag to over 20+ polyps in a colony so i have a feeling these levels will get ate up very quickly now.

one of the issues i see is that adding alk will raise my PH some, my ph at night is usually 8.25-8.3 and daily it is 8.4-8.5 so raising it might cause a disaster. i see that BRS as a 2 part that says "lowers ph" and one that says "raises ph" i am not sure which to choose? i think my PH level is fine now and if it lower it then it might be to low and if i raise it then it will be to high. which do i choose?

any info is greatly appreciated!

i also have a home made top off with 2 float relays that trigger my top off pump (just a small maxijet in a 5 gallon bucket) and i usually use roughyl 5 gallons a week of top off. what are the chances that i can just add the 2 part solution to the top off water and let it just naturally add it to my tank and have it be accurate? i assume the evaporation rate in my tank is fairly steady so it should top off the same but how do i figure out how much i need to add to say 5 gallons of top off water to get my levels in a good range? do i just trial it at a low amount first and slowly bump it up or is there a calculator for it?

my tank info

29g tank
10g sump
4x 24w t5 HO bulbs
eshpps psk-75 protein skimmer
home made ATO

i ask to please give good thorough answers so that if anyone else has 2 part questions they can refer to this thread for information.

Thanks!