View Full Version : Help! Accidentally spiked Alk (and pH)

07/04/2017, 05:48 PM
What a dumb mistake! My Mag was down just under 1170, so I was went to add BRS Mag mix. Stupidly, I picked up the BRS soda ash and added either 7 or 10.5 ounces before the Apex went off from a pH spike.

The pH is over the range of the Salifert test. The Apex indicates that the pH went from 8.42 to 8.88.

Alk went from 8.9dKH to 12.4dKH.

I did some searches and it appears that I'm probably best off not doing anything. Found this old thread:


I don't have a lot of corals in the tank. I do have a trumpet coral that is struggling from my cyano issues/fight. I also have a flower anemone, a candelabra and whatever this thing is:

http://i1245.photobucket.com/albums/gg600/Hitch08/DSC_7437-1_zps7vwdol15.jpg (http://s1245.photobucket.com/user/Hitch08/media/DSC_7437-1_zps7vwdol15.jpg.html)

^ That's an old picture, from the first day that I got it.

Other than that, several fish, a sea cucumber, some snails in the DT and some crabs in the refugium, a black serpent star, etc.

I have probably 40 gallons of fresh water, so I could do a change if that's recommended.

Any thoughts/recommendations on the following would be greatly appreciated:

1. Should I try to bring down the pH/Alk.
2. Should I go ahead and start to bring up the Mag? Or, should I wait several days?


07/04/2017, 06:16 PM
Water change. Do a large water change.

07/04/2017, 06:54 PM
Let it be, it will go down.

Martin Kuhn
07/04/2017, 08:06 PM
No need to react to the higher KH and also ph. Wait, they will come down.

That's better because of less stress than another change to the tank for corrrective measures.

Adapt Mg with the correct stock solution or MgCL2

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07/04/2017, 09:29 PM
I would turn the lights off for a day and slowly bring it back up.
My experience with Alk spikes is that they can be mitigated by reduced light until the chemistry comes back into balance. No explanation - just experience.

07/04/2017, 09:50 PM
As your lights come on for the day of course your alk is going to rise but nevertheless just ride it out for a few days.Still going to drop regardless.

07/05/2017, 08:50 AM
in your case, do nothing, as your ph is below 9.
unless you do a 100% water change, your ph drop will not be significant doing partial water changes. just leave it alone.

this is what my tank looked like when my old ac jr controller got stuck and dosed everything into my tank. I just did water change till ph was below 9 and left everything alone. Everything was fine.


07/05/2017, 10:01 AM
I really didn't know what to do last night. Most of the suggestions here and in other threads were to leave it alone. Once I saw that the pH of my salt was likely into the 8.x range, it seemed like a big water change wasn't likely to do anything significant. I decided to leave it alone.

I'll check out the tank when I get home tonight to see how things are doing. Thanks for all of the posts!

07/05/2017, 11:10 AM
pH doesn't matter. Alkalinity does. Keep lights off and do small water changes until you're back to where you want to be.

To relieve pH, you just need to aerate- but again, it doesn't matter.

07/05/2017, 12:07 PM
when I had that happen to my tank, I found this thread with Randy Farley Holmes stating the opposite, ph matters but alk does not. and the recommendation is to bring down ph below 8.6. (correction to my earlier post saying below 9).


Martin Kuhn
07/05/2017, 12:16 PM
Ph in saltwater tanks is of MUCH less interest and MUCH less controllable than in sweet water

Normally we (salt water) have issues that deal with too low ph. Solutions recommended and absolutely meaningful are "improving aeration" and "reducing possible fouling in your tank"

What would you do in case of too high ph ?
Connecting CO2 to your tank as in sweet water ?
I wouldn't.

Leave it alone and it will come down with less stress for your animals

.... of course and as always ... just my opinion

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07/05/2017, 12:17 PM
That's circa 2008. On his more recent postings, I think there is more emphasis on Alkalinity. Also, he says not to bother measuring it because it's meaningless to measure, not that it doesn't matter. Alkalinity spikes drive RTN.

pH above 8.6 isn't ideal but it naturally comes down with aeration (natural rebalance of CO2 between the air and water)

07/05/2017, 12:19 PM
I'll let readers decide to choose between Randy Farley Holmes statement and other's opinions. :)

Martin Kuhn
07/05/2017, 12:37 PM
Typically most of what you read in forums is "opinions"

Posting lengthy articles links which at least leave the interested reefer alone with some questions in my eyes is "easy"
But not what the person asking for help is really looking for.
Even if the link articles of someone who is believed to be a valid expert.

I believe that "straight to the point" suggestions is more what Mr/Mrs "Forum User" is looking for. Especially in cases is expected emergency.

To be honest: who of us reefers did not "over reacted" at least 1 time with his tank, recognizing later on this wasn't a too good idea ?
..... again .... just my opinion

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07/05/2017, 03:51 PM
my opinions are based on personal experience and success. I trust them... and everyone is free to try and share their successes or failures so we can all get smarter together.


07/05/2017, 04:09 PM
pH at about 8.9 is high enough that it might cause some damage, at least if the level was sustained. As stated, aeration should bring the pH back down quickly. As long as the animals are doing well, I'd just wait. If anything started going downhill, I'd do some water changes. If the pH isn't down to 8.6 or below fairly quickly, some seltzer water should help, but it's seldom necessary. The alkalinity should drop on its own, too.

Most often, tanks come through this type of event with little or no damage, but every tank is different.

07/06/2017, 08:56 AM
As of this morning, the pH is down to 8.40. Inhabitants seem to be doing OK as of last night - lights were still off this morning when I left for work.