More Confusing Chemistry

[patchin]

Calibrated ph probe and started monitoring ph. Read 7.9. Alk was 6.5-7 so I figured I'd raise it and the ph at the same time. Added 2 oz of two part alk and ph went DOWN to 7.85. Huh??
What's going on?

 

[Mr. Ugly]

What volume of tank?

2 oz is way too much if it's the 12g nano.

If you OD on 2 part, you can precipitate your alk and calcium and drop your pH.

 

[patchin]

oh yeh, it's in the 50 ga.

 

[patchin]

One more thing. Everything in the tank looks good except for one hammer which has shrunk and one part has a "string" hanging off of it.

 

[iani]

Also what are you using as your ALK portion of two part? Is it home made or is it b-ionic. If you are used baking soda of the ALK it will drop your pH.

 

[patchin]

Yes, it's homemade with baking soda. I thought that would raise it. I guess I need to read up on it. I could have sworn it said on the two part website that the alk part would RAISE the ph.

 

[tonggao]

I believe baking soda will raise the ph also.

 

[patchin]

My mistake. If you make the recipe with SODA ASH, it raises ph. If you make it with BAKING SODA, ir lowers ph temporarily. Is soda ash a separate chemical than baking soda, or just baked baking soda? if different, I think it can be purchased from Leslies?

 

[iani]

Baking soda lowers pH because it is a very weak base and it buffers the water below your typical pH of salt water. Soda ash (baked baking soda) is a slightly stronger base with therefore with buffer the water to a pH a little higher than your salt water.

 

[patchin]

So I should bake my baking soda and redo my formula, Bake for how long? 1 hr? What temp?

 

[sfsuphysics]

I'm assuming your testing your pH with an electronic tester? Either way I wouldn't worry too much about 1/20th of a point swing in pH, you get more than that over night when your lights are out.

 

[patchin]

Is a ph of 7.9 detrimental to the corals' growth? I'm concerned cause one of my hammers is kinda struggling when it's been very healthy. kinda melting one one side??

 

[Thales]

[quote author=patchin link=topic=3240.msg36276#msg36276 date=1204688228]
Is a ph of 7.9 detrimental to the corals' growth? I'm concerned cause one of my hammers is kinda struggling when it's been very healthy. kinda melting one one side??
[/quote]


What time did you measure your pH? It will be lower in the morning than in the evening.
I don't bother to try to adjust pH because the adjustments are short term and too finicky. 7.9 should be fine, but I want to know what time you tested.

 

[patchin]

Tested in the evening before lights went out. This morning ph is 7.2. To me, that's scary. But heh, I'm just a beginner. Opinions, please

 

[Thales]

I don't believe 7.2. How did you calibrate your probe and what kind monitor is it?

 

[GreshamH]

I do, I've seen my old tank at 7.2

Matt's (you know who Rich) tank tested out really low the other day as well, 7.5 I think.

 

[patchin]

AcII unit calibrated with 7.0 and 10.0 calibration fluid. The fluid was given to me when I purchased the unit. Supposed to lab grade fluids. Unfortunately I don'r have any other way to test the ph. I was given a Milwaukee pen style meter, but I could never get it to work right. May have dried out or something?

Note:
This is a tank where nothing really grows well. Corals just sit there without doing much. Mushrooms are about the only things that grow.

 

[kinetic]

you could also grab a test kit for pH at a petco or LFS, might give you another reference, see if there's a huge discrepency.

 

[Mr. Ugly]

Mix a new batch of saltwater and test the pH on that?

 

[patchin]

Good idea. The ph of instant ocean is?????