Alk dropping in newish tank with no corals

BrotatoSalad

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My alkalinity is staying at 7 with Red Sea coral pro salt as my mix. What’s my next move?

To preface this a little, I’ve been reefing for 6 or 7 years but don’t have much experience with a dry rock and sand start.

The tank has been wet for about two months I think. Nitrogen cycle was done with Dr Tim’s and the rest of the good stuff is being added by AquaForest Lifesource. My alkalinity has consistently been at or around 7 on the Hanna checker in the tank. My salt is Red Sea pro which should mix to 11.5 and alk tests on freshly mixed salt show 10+ (Hanna checker can be finicky sometimes). Salinity is 1.025 and verified against the tropic Marin floating hydrometer (not a swing arm).

I found a similar question asked prior and Randy noted that dry rock can use up alk, but I’m curious on my next move to get it to stop. I plan on doing acros only in this tank, but want the tank’s alk closer to what my salt mixes to before adding anything that needs it. If the solution is just to wait it out that’s fine, but if there is a trick to getting the rock to stop binding this stuff I’d be happy to hear

Tank currently just has one Banggai Cardinal being fed heavily with frozen mysis.

Filtration is just filter floss and a skimmer that’s pretty much just bubbling right now. Pulls out some funk but over the week, there is maybe 1/4inch of gunk in the cup.

Phosphates are 0 which I’m not super concerned with as I’ve read dry rock can bind that as well.

Posted from mobile so please excuse any typos or strange formatting
 
Is MG 1350-1400ppm?
low MG can result in inaccurate Alk test results.
Other than that, I can’t see using RS Pro, no Stoney load, and end up with 7 dkh.
 
Is MG 1350-1400ppm?
low MG can result in inaccurate Alk test results.
Other than that, I can’t see using RS Pro, no Stoney load, and end up with 7 dkh.
Unfortunately I don’t have a MG test yet. Figured I’d wait to get that closer to coral time, but I agree. This tank has seen no water outside of RS pro that was tested prior to going in for alk in all of its elevated glory. I would assume that MG is within normal ranges but can’t verify. I’ll pick up a test tomorrow when I grab the pistol and goby pair.
 
I haven’t, but tests on the tank and freshly mixed salt water have both shown consistent numbers. 7ish on the tank and 10ish on the fresh salt.
The fresh showing 10 and the tank showing 7 would lead me to believe your magnesium is out of range ie below 1300, that is just my opinion.
 
The fresh showing 10 and the tank showing 7 would lead me to believe your magnesium is out of range ie below 1300, that is just my opinion.
I’ll grab a test tomorrow to confirm, but what do you think is removing the magnesium in the tank? More dry rock binding?
 
With no coral present, it is not an issue now but see wwhat your calcium level is as alk and CA work in balance
 
I’ll grab a test tomorrow to confirm, but what do you think is removing the magnesium in the tank? More dry rock binding?
Yeah binding would be my thoughts, also I have noticed a lot of salt mixes claim a certain major element value but what you actually get once you mix it with RODI isn't always as stated on the bucket, some experiences may vary.
 
To add, here’s the thread Randy responded to regarding dry rock binding things and lowering alk. I understand that alk drops alongside the others in the big three, my question is if I can do anything to stop the rocks from binding, or if this is a typical part of a dry rock start and stay the course.
 
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With no coral present, it is not an issue now but see wwhat your calcium level is as alk and CA work in balance
Planning to grab cal and MG tomorrow and break out the ol’ titrator and confirm if those are dropping alongside. I wouldn’t be surprised if they are dropping too due to binding, I’m mainly curious if I can do anything to stop the rocks from binding. If it’s a wait it out thing I have no issues with it.
 
The thread mentioned above has some good info and suggestions.
Rereading it again, it seems like stay the course and ruin the seed crystals with mag and phosphates is the way to go. Not sure how or why I didn’t remember those details on my initial reading lol.
 

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