I think I did a bad thing - pH

So I was checking levels. The pH in the 110 was a little high - 8.5 and in the 29 it was 7.9 - 8.0. not too far off but I had to mess with it. Of course I didn't have the right tool for the job but I had a gallon of pH up and a gallon of pH down, both made by General Hydroponics. I added about 15 ml to the 110 and 4 ml to the 29.

I noticed that my Xenia retracted (may have gone way low locally). When I added it to the 29 (pH down) I saw a little precipitate drop out.

What did I just do?

 

Ahhhh not good! Especially if it formed a precipitate...
Next time you should mix in a little bit if water to dillute it and possibly add slowly to the DT so it's not a fast transition for your corals or fish.

Now about your coral, did precipitate land on it?

 

No it did not.

I was adding it drop by drop via a syringe in front of a Koralia. I saw the participate form as soon as it hit the water but as it was mixed in the flow it re-dissolved.

Why do you say not good? Explain

Xenia was back out in a few - that one got the pH down.

So a little quick research has yielded my pH adulterants ** MAY ** contain UP: KOH Potassium Hydroxide DOWN: H3PO4 Phosphoric acid.

Is phosphoric acid anyway related to phosphates?

 

Most pH lowering products work by binding with carbonates in the water. I would recommend checking your KH.

EDIT: I would look at the bottle. I'm not aware of any pH Down products for marine usage....they are normally for freshwater planted tanks.

 

No KH, Alk is 2.4-2.6

What's the conversion?

Everybody is looking fine so far. Gregonian' polyps are out, zoanthaids, and nepthea too. Xenia has been back and forth though. All the way extended then retracted almost to the stalks

That 15 ml dropped the 110 about a half of point. A lot pretty quick I think...is it? I looked at the invertebrates and they are all ok, emerald crabs, red & blue legs, peppermint shrimp.

Did I get away with it?

 

Here's a conversion chart. ReefChat - Alkalinity Conversion

It looks like some of your alkalinity precipitated out. If you only keep softies, it wouldn't be a big deal but ideally you would want it a little higher.

 

and about the phosphoric acid...
when the H3PO4 enters the water, it will want to immediatly come to an equilibrium energy level with the water. aka one of the H+ molecules will dissociate from the H3PO4 to the H2O leaving you with H2PO4-. All H3PO4's will dissociate the H very easily (thus the decrease in pH). but after this, the H2PO4 is more tightly bound so it will only dissociate another H+ if it still has to come to equilibrium with the H2O (with such a case it probably did).
Bottom line is you probably have a bunch of H2PO4- or else HPO4-2 floating around. because of the structure, this can be skimmed out but the H2PO4- can also be used as a GREAT fuel for hair or bubble algae. Id look into some different brands

 

Freakin' awesome explanation. That's the kind of stuff that excites me. Studying chemistry.

K+