Low Calc & Mag while 2 parting

[blazin]

Hey guys,

Ive been using the 2 part solution from bulkreef for about 7 months now...everything's been doing great in my tank, until recently I noticed a slow down in my SPS growth. Also my pH used to be 8.3 but now its 7.6 with the lights off and 7.9 after full photoperiod.

When I first started dosing, I manually adjusted my alk, ca, and mg to the appropriate recommended levels..

For the first month, I religiously checked the alk and ca and they were right on track at about 8 dkh and 420 ca. Lately, I've just been checking the alk (about once a week) and its always at 7-8

I havent been checking the calc recently, until tonight.

My calc is at 340, and I checked my Mg, it was at 1140

I only dose about 25mL a day, so im still on the same gallon jugs after 7 months...but they are just about empty (probably a few more weeks)

Now the 3rd Mg package you get is supposed to be dosed when the gallon jugs are over. I havent done that yet...

My questions are:

1. Why is alk on track and ca is low when I've been dosing the same the entire time?

2. What about the Mg? Should I add the pouch now? Is the kit designed for those who dose larger amounts and go thru the gallons much quicker?

Thanks!

 

[HighlandReefer]

Assuming your test kits are not old and are not faulty, the most common reason for your results would be the salt mix you are using. If your salt mix has a high alk. and a low calcium content & a low magnesium content like Instant Ocean, then perhaps it will be better to supplement the calcium and the mag. at water change time.

As far as your pH, the first thing I would check is your pH meter (if you are using one. pH test kits are not very accurate). I would re-calibrate with both calibrating solutions and re-check your pH first. You should be re-calibrating your pH meter monthly. If this does not work, then I would take a cup of your tank water out of your system and check the pH of it, to make sure there is no electrical interference.