ALK overdose. Left Doser on for over 5 hours. Send help! :(

[B_Salty]

So I accidentally left my alk Doser on for 5.5 hours and it dumped 1180ml of alk into my tank. Dkh was at 7.8 and I wanted to slightly bump it up to my normal 8-8.5 dkh parameters, had an emergency call from work and I totally forgot to turn my apex Doser off.

I came home and the tank glass, sump, power heads, and rocks were covered with precipitation. Also noticed small areas of sand were starting to harden. It took me about 16 hours to physically get to my tank. (I work as a traveler and was about a 6hr drive away). First thing I did was test.

PH 8.3
Temp 77.8
Salinity 1.026
DKH 6.24
CA 366
Mag 1418
PO4 0.0
No3 0.0


Tank setup:

Fiji cube shallow 76 gal
Trigger platinum 26 sump (roller)
NYOS 160 skimmer
Tunze macro algae reactor
BRS dual reactor (GFO & Carbon)
Full apex system
Radion XR15 x2
Ai prime blades x2
2 mp10s
Vectra M2

When I first realized I forgot to turn the Doser off the Ph spiked to 8.9 but then immediately came down to 8.1-8.3 and stabilized. I ended up cleaning the glass and rocks from all the precipitate to hopefully have the roller and skimmer grab as much of it as possible. I’m currently prepping for a water change.

My question is what should I do next? 10%, 20%, 50% water change? Should I dose ALK and CA to get values back up? And also with dumping so much ALK in the system why is my dkh only 6.24? I was so scared it would be like 15-20. Fish and coral look great with no signs of distress. The corals are all open with full polyp extension. I’m so angry at myself for forgetting to turn the Doser off and a bit discouraged at the moment. Any help/advice would be much appreciated.

 

[boacvh]

Same happened to me. You can see pictures of my milky tank on my build thread.
I solved it by doing as big water changes as I could over the following days. Whatever my water station size permitted, I changed. Start with a 50 and go from there.

 

[elysics]

Raise up calcium in steps, slowly raise alkalinity over the course of days and siphon the white stuff out because it's ugly. Take out chunks of hardened sand and replace if you can.

It's only so low because it got so high it cause a calcium storm, like a cloud that gets so wet and stops being a cloud and starts being rain. It probably was 15-20 or something close to that at some point. It snowed calcium carbonate in your tank.

But now the storm is over, what's done is done, slowly stabilise the system.

 

[Randy Holmes-Farley]

Trying to raise alk right away will result in more precipitation. Go slow or just wait. 6.2 dKH is not a huge issue.

 

[ukgeoff]

Hey Salty, don't worry, you're not alone. I've made this same mistake twice on my Apex, accidentally setting the doser to on, rather than auto.

The first time, I dosed about a litre of Randy's concentrated nitrate into my tank and the next time, I dosed a half litre of all for reef into my 120l nano tank.

I did about eight 10% water changes the first time I overdosed, but this had such a small effect it was hardly worth it. I was up all night making water and changing it. Eventually, I realised that to get my nitrate to an acceptable level, I needed to replace more than 10% of my tank water at a time.

The 2nd time I overdosed, I did an immediate 85% water change, which got things back to normal quickly. It was also probably less stressful on my tank inhabitants doing a single 85% water change. The only issue I had with an 85% water change was finding enough containers to make so much water.

Good luck and I hope you get everything back to normal.