Damn Parameters!!!

Try bumping up the mag to 1450 and see if it makes any difference. I had the exact same problem as you and when I bumped up the mag the alk would stay up.

 

OK will give it a go, Thank you.

 

With that amount of stock or should i say so little, i would first ask the question what salt mix are you using? and how often are you preforming water changes? you shouldnt have to dose with that amount of coral in a 50g tank unless they are gigantic monster corals which i doubt. Your alk is what worrys me the most

 

I agree unless you see your corals stressing or dying I wouldn't worry about it, An alk of 6-7 is completely fine and will not harm a thing, i Keep mine at 6-7 because I carbon dose and my sps go nuts so imo there's no reason to try and raise your alk unless your having problems with coral, Waterchanges should be more then enough to keep your tank stable you should not have to dose right now so let us know what salt mix your using like mentioned above and hopefully we can get this figured out.

 

I use instant ocean marine salt, 25kg bucket
I also have 2 brain corals one is 2" the other is 4" and a mass of mushrooms
Could not think what I had the other day, I now do water changes 25% every Sunday as I use to but I think the thing that started it was I did not do a water change for a month due to moving out for a while and my problem as been getting it up since the alk used to be 4, I know shocking

I want a way I can use the goods I have bought to keep my parameters where I want them and stable.

 

Low Alk. can be caused by atmospheric conditions.As long as low Mag,and calcium are ruled out.(you don't have much to worry about with that salt ) If possible try running your skimmer air input to receive fresh air.
Are your windows closed??;D

 

Also be aware that these numbers will change depending on the time of day.Be sure to test at or around the same time each day.Alk. will be lowest right before lights on (typically).This is why most like to dose at night or in the morning.Are you seeing any precipitation??
While you may or may not be able to purchase from this vendor you may be able to find the ingredients in bulk.
IME It is best to start with Mag. levels because they are the key.Once you have it raised to between 1300-1400 retest Alk./Calcium and adjust where needed.

BRS 2 Part Calcium & Alkalinity Total Package - Bulk - Bulk Reef Supply