Suggestions on post-doser failure

[zedxplorer]

Hey all. Recently I had a doser failure due to Google automation screwed up the timing of the doser. Instead of dosing all for reef for 5 minutes, my automation sent the on signal to the doser pump 5 minutes late, behind both the off signal and a back up safety off signal. So my dosing pumps stuck on for the entire night.

The morning after (2 days ago), the clown died immediately, along with all the pods, shrimps, and sea stars. The goby was struggling and died the day after. Corals are stressed, very puffed up with mouth semi open. But so far doing ok and it's a euphyllia tank so mostly torches, hammer, and frogspawn. They are still chugging along.

I measured the alk that morning and it was at 17.3 dkh with Hanna, so I did a 75% water change bringing it down to 12.7 dkh. But today I measured the alk again and it's at 16 dkh. What can cause this alk increase without any alkalinity input (doser unplugged and pulled)? I use tropic marin so the salt alk is 8dkh, and my rodi still doing 0 TDS.

Any suggestions are welcome, and if anyone had to deal with similar scenarios before any pointers on how to safely bring the alk back down? Right now I am just testing and doing large water (aim to at least down to 12ish) and hoping it doesn't stress the corals too much.

 

[dz6t]

That is the issue for all-for-reef.
This reagent requires bacteria to break it down and generate carbon dioxide inside the tank to supplement alkalinity.
It takes time for the bacteria to do its job that is why alkalinity will continue to increase over time. Also you won’t get the instant boost of alkalinity such as two-part dosing.
Certain bacteria will convert All-for-reef to formaldehyde which is highly toxic.
Your pH may also crash too.
It is also a form of carbon dosing, so the oxygen level will drop to dangerous levels when over dose and kill the fish.

 

[zedxplorer]

That is actually very good to know. I am very new to dosing and been relying on weekly WC to resupply the alk. What do you think my best option is right now? Will large WC sufficient to remove enough AFR from the water column?

 

[dz6t]

The best option is more large water change to purge out the remaining AFR. There is no other effective way to remove this chemical as it is not exported by skimmer much due to it is a very small molecule and highly water soluble.

 

[dz6t]

You can also run activated carbon aggressively.
One cup of carbon per 50 gallon of tank volume, replace carbon the next day, do this 2 to 3 times. Check alkalinity daily to see if alkalinity continues to go up, if alk goes up, there is AFR remaining. Use two-part dosing such as ESV instead.

 

[FishieBusiness]

You can also run activated carbon aggressively.
One cup of carbon per 50 gallon of tank volume, replace carbon the next day, do this 2 to 3 times. Check alkalinity daily to see if alkalinity continues to go up, if alk goes up, there is AFR remaining. Use two-part dosing such as ESV instead.

ESV all the way. Have had the best results dosing with it. Not the cheapest option out there but very effective.

 

[afboundguy]

Bulk Reef Supply two part is super cheap and you can make it yourself. Not sure if you have automation but you can build in redundancy if you have a pH probe and if it gets too high/low you can trigger it to shut the dosing pump off.

 

[zedxplorer]

Thank you everyone for your input! They are very helpful and appreciate the advice going forward. I did another 90% WC today and the corals are still chugging along, although definitely stressed. Fingers crossed that the alk doesn't stay increasing the coming days and hope they can ride out this wave.

 

[zedxplorer]

I figured I'll follow up on this - good news my tank has stabilized after 5 days and so far no coral loss. There are definitely short term damage on the flesh band of my euphyllia due to stress, but as of yesterday they have all opened up like normal as before the crash. Checked all my parameters and all seems normal, except a slightly high alkalinity of 10 (I usually do 8).

Day 1 - alk 17.3, did 80% water change with 8dkh water, return back to 12
Day 2 - did nothing, since I was not aware AFR is a biological process
Day 3 - alk back to 17.8, did another 80% WC, back down to 12.3, hooked up an HOB filter loaded with activated carbon as @dz6t recommended. It helped a ton purging out the remaining AFR and stabilizing my water
Day 4 - alk of 12.5, seems to have stabilized, did 50% water change, bringing alk down to 10.3
Day 5 - all parameters normal, alk 9.6, seems to have stabilized, corals back to normal state, no loss so far

Unfortunately I did lost all the fish (only a clown and goby in that 15g nano tank), all the pods and critters, and a tuxedo urchin. So not a big loss, I managed to move all the other inverts to my bigger 40g. Now they are back to the 15g.

One thing I would say I am glad about AFR though is fortunately it is a biological process and it raises all rather slow. If similar doser failure happened with direct dosing, my corals may be all wiped out...I guess that's a silver lining when the doser dumped 250ml of liquid instead of 5ml. Did burnt through half bucket of salt but that's worth it saving the coral lol.