Slight Emergency- 4 DKH Alk Drop

[cdw79]

I refilled my Alk reservoir last night after running out on Saturday. What I believed happened was that a few weeks ago before I realized it was low, my Alk kept dropping from the 7.5 range I normally keep it to about 6.8, presumably because it was sucking out the very last drops of fluid. Like an idiot, I then increased the default output to try and mitigate that issue. Well sure enough, once primed with new fluid, the Alk exploded- 6.9 to 11.7 in a matter of hours. Just ran a second Alk test and got 11.0 this morning, so at least I know it's hit its peak (was worried it would come back even worse since the last test was at 1 am).

The tank has been set up for a year and a half and I have SPS, LPS, Clams, etc. I'm kind of at a loss as to what to do, if anything. I cut off the default Alk to 1 ml per day (lowest it would go on the apex) to try and not double down on the issue, at the very least. But is this even a good idea, then? I know the Alk levels won't lurch down as quickly as they went up but idk if I should still have some calc coming in Looking over the tank today I don't see any signs of any kind of necrosis, which I guess is good, but we're still only 8 or so hours into the alk overdose so I assume the worst is yet to come. Both clams are open and seemingly doing ok for now. No shrimp or anything and only crabs are a few hermits. 

Is there anything I should do? I'd fear a huge WC might get the DKH down to some degree, but would a potential lurch back be a good outcome as opposed to just trying to stabilize things? I dealt with these a bit a year ago or so, but I didn't have such a packed tank at the time, much less one with a decent amount of higher end stuff either. Just baffled at how I've managed to do this, any and all thoughts are greatly appreciated.

 

[beatle]

I didn't think high alk was a problem unless you were also going through the early stages of a tank with ammonia present (kills fish), or if you have an ultra low nutrient system (burns tips).  Either way, 11.7 is not very high.  I've seen that 12 dKH is usually a suggested upper limit, but I've also seen some people run even higher than that.

 

Bottom line, I wouldn't worry about your alk right now and let it come down naturally if you'd like to run it lower.  Not sure about lowering alk, but BRS recommends only raising alk by 1.4 dkh or less in a day.

 

More importantly, I would check on your dosing setup.  I also rely on dosing pumps for water changes and additives, but they are really the only things that have screwed up my tank when there's a fault.  And faults are not always as obvious as a pump or line leaking.  But because I know how lazy I am, they are a necessary evil.  Checking on them is less work than actually doing work.

[cdw79]

It's definitely fully on me, I'm working on how I'll mitigate a similar cocktail of issues in the future. Growing pains from a fish keeper to a proper reefer.

 

Ultimately I know 11.7 is within an acceptable range, I'm more so concerned at the speed at which it got there. The 4 dkh spike in a matter of hours makes me anxious, but so far the corals look unaffected. Probably too early to tell but we'll see...

[Origami]

A 4 dKH spike in a matter of hours is high and 11.7 dKH is on the high side of normal. You can go too high, but unless you're running a ULNS (ultra-low nutrient system), higher alk (>8 dKH) should not cause great harm. Shut down your dosing and let consumption bring your levels down. 

 

Here's something that I posted back in 2009 about responding to a kalk overdose.

[cdw79]

I've gone ahead and done a WC as a precaution, but even if 11.7 is within range, as I understood the rapid increase could nonetheless be an issue?

[DaJMasta]

The corals and clams won't be happy with it, and I wouldn't be surprised to see a slight stunt in growth rates or abnormal coloration/polyp extension - but it's not likely going to kill anything.  A big swing is a stressor, but since it was basically still at a reasonable level on the low and high side, I doubt you'll see significant, lasting effects.

[YHSublime]

A water change, and let it ride till you get back to your normal dKH levels. Even if it went up fast, let it take it's time to come down.