just did water change now parameters are all off

[cheezefrog]

I did a weekly water change on my 36gal system with RC now my Calcium and Mag are way off, Alk is the same but I just don't get it...This is always happening and I cannot for the life of me figure out a stable dosing and water change routine when its changing so much....

Before water change:
Cal 420ppm
Alk 8.0-8.1dKH
Mag 1440ppm

Now its:
Cal 400ppm
Alk 8.0-8.1dKH
Mag 1290ppm


I have been wanting to try out my new 2 part ESV products but its ridiculous to dump this much stuff in a small system to bring it up to par again. Reef calculator for ESV products are showing 45mL for Cal dosing, none for Alk, and Mag 108mL....I just do not understand how to use a 2 part buffer system when its this drastic of parameter swings, especially when no alk is needed and when a water change is lowering parameters this much. Obviously dosing Alk as the secondary doesn't seem required since its normal for my taste, so I do not understand how to figure out a stable and routine balance based on daily dosing and weekly water changes.

[jbb]

some of the elements in the salt may have settled to the bottom of the bucket, give her a good shake before the next batch and see if that helps. If not, you might be able to dose the new mix to the desired levels before the change, or switch to a different salt that gives you the desired levels. DO NOT try to reach your regular limits in one dose, you can cause a lot of damage that way - go slow.

[cheezefrog]

I've been using RC for about a year now, because IO did not seem to be able to maintain my Alk and Cal levels. I was sort of shocked to see Alk the same, because after reading some articles and threads on RC mix there was some notice to not let it mix longer than 4hours because Alk levels will drop, which is one parameter I'm always fighting because its being absorbed so much.

 

I actually let this water change mix sit for almost 24hrs before throwing it in my tank. Short of vacuuming my sand bed this time I did nothing different than the normal.

 

I am mixing another batch to do another water change and see if it brings up the levels without having to dose that much, it just seemed crazy in my opinion to see a drop of over 100+ppm in Magnesium. I know my Cal and Alk are getting soaked up pretty good a 20ppm drop is fairly common with all my SPS/LPS but is just seemed odd in my opinion after this water change today.

[jbb]

I know with my RSCP , the levels seem to drop off if mixed too long . Try mixing for maybe only 3-4 hours and see what it does.