Low Alk, High Ca & Mg with Triton. Why & what to do?

[PiscesPower]

Here are the questions in case you don't want to read the history.

What would cause the differences in uptake of Alk, Ca & Mg?

Would a sand sifting goby, tearing up a relatively new sandbed cause an increase in Ca & Mg from the sand?

What should I do to raise Alk without increasing Ca & Mg?

History of the issue at hand.

Tank RSR 250 with a DIY, undersized fuge, only about 9% of volume, my build thread has images of my sump. This system was an upgrade of a 24g cube back on September 1st 2017.

I am doing Triton since September 1, with my tank upgrade. I have not had any nutrient issues to speak of however in the last few weeks my Alk has been dropping but Ca & Mg have stayed on the high side. Today Alk is 7.1 and 6.8 repeated with a new reagent bottle in Hanna checker Ca 494 (Hanna) Mg 1440 (Saifert). 11/19 was at 7.7, 430 and 1480 respectively. I didn't change my dose on the 19th, despite alk going down a bit. I was trying to stay status quo until I got my ICP results back. (Should be within the next week). My original Ca & Mg, on my first ICP were low and back in September and the beginning of October I was dosing Ca & Mg per Triton instructions, but have not done any in weeks.

I'm running a mixed reef with newly added (within the last 2 months) sps frags. Most of the LPS and zoas came from my previous tank. I'm seeing encrusting on the sps, but not great polyp extension. I also have a bunch of small BTAs and 2 medium sized. Truly, other than the limited polyp extension, everything looks pretty good and is growing well. Pic is from a few minutes ago.

May be coincidence, maybe not but I added a 3" sand sifting goby a few weeks ago and it was after he has been disrupting the sand bed (new with tank upgrade) that I have had the increased Ca & Mg.

I've checked my dosing pump etc, and I am pretty confident that all is working as it should and my testing accuracy is good. I tested volumes last week to be sure that they are dosing correctly, since this trend has been doing on for a few weeks.

This is a duplicate post from the Triton FB page, but I thought maybe some additional input, maybe from @Randy Holmes-Farley.

I haven't really found information on how to manage unbalanced results, since I should be dosing equally.

 

[Jason mack]

I had a similar problem .. found out my dosing pump was broken .. after i got a new one i needed too lower my Calc and mag .. so i just stopped dosing bottles 1,2 and after a couple of weeks when they came down i just started slowly building the dose up till iT matched what i was dosing 3a-3b .. i was testing all 3 Every 2 days during this ..

 

[PiscesPower]

I'm debating ordering a new one, since was used when I got it. It seems to be accurate, but who knows.

 

[Jason mack]

I'm debating ordering a new one, since was used when I got it. It seems to be accurate, but who knows.

Check the weight of Your bottles / containers ..

 

[PiscesPower]

I checked the volumes a few weeks ago. I changed dosing containers after I had an issue where one of my tubings got separated and contaminated my Bottle 2. Since I had to clean out the vessel, I decided to switch to Voss bottles. When doing that, since I needed to change tubing as well, I went ahead and checked volume. It was correct for a single dose carried out. I set for 50 mls and it dosed 50 mls, tested each head. Still, its a bit noisy and it only has 3 heads, so I may yet replace it.

 

[Scott.h]

I'm not sure what tim would recommend. Personally I think if you want to raise alk and lower cal and mg I'd just add alk for a bit by itself. It's not going to hurt anything. Or leave it. You said cal was 430? That's not too high. If calcium or magnesium are a bit elevated it won't hurt anything either. If you want your alk at 8.0, just raise it over a few days and keep going equal parts after that. Myself, I haven't did a calcium or magnesium test on my own since June. I just closely watch alk. I do keep my sps tank alk at 7.0-7.3. Both triton tests came back good. . I think my calcium was higher then I used to keep it at 470 or so, but it's no concern to me.

Are you using a quality dosing pump? If you are second guessing that, I'd make sure all parts are equal. One element may rise higher like the situation you are in even if it's not the pump, depending on the corals.