Alkalinity and PH

emart805 · Jan 12, 2024

Phosphate = 0.12 (Hanna)
Ammonia = 0 (API)
Nitrate = 0 (API)
Nitrite = 0 (API)

I’m having trouble getting my alkalinity above 8 without increasing PH. My tank is about 8 months old and I have the following equipment (trying to build for SPS dominated mixed reef):

- Innovative Marine INT 112 Lagoon - DIMS: 35.4” x 35.4” x 19.7"
- 2x XR30 Pro Lights G6 - set to 60%
- 2x MP40 - set to 75%
- Coralife Turbo-Twist UV Fish Tank Sterilizer 6X, Up to 250 Gallons
- PaxBellum N24
- Red Sea Skimmer 300
- JBJ Arctica 1/3hp chiller
- 30g Trigger Systems sump (CRYS30S)
- about 75lbs marco dry rock (starting to encrust)
- I've added pod populations and have been feeding Reef Roids and phyto daily.
- I have a powder blue tang, a blue eyed tang and one clown fish (I had more fish but they caught a nasty virus

that killed many overnight--the survivors made it through QT)

I'm currently dosing Two Little Fishies ATLCB4B C-Balance (A&B) 16ml per day, two hours apart. Part A is dosed between 17:00 and 21:00 and Part B is dosed between 00:00 and 05:00. I've had to use soda water to lower PH a few times and it works temporarily, but I can't seem to get ALK over 8.

I currently have only a 4 SPS frags in my tank and a couple of LPS frags, so I don't think the demands are necessarily high. However, I did lose a few frags and given the parameters I just can't explain why.

1. Can you give me advise on how to increase ALK without increasing PH (specific products I could use and in what quantities and intervals)?
2. Do you see anything in my current parameters that would explain past coral RTN?

Thanks in advance!

Randy Holmes-Farley · Jan 12, 2024

Your alk is fine, and the pH would not hurt to rise a lot (I wouldn't go above about pH 8.55), and in any case, you can boost alk with baking soda that won't raise pH.

So all the problems disappear, no matter what you do.

I see no chemical reason here for the RTN, but I'd stop adding soda water.

emart805 · Jan 12, 2024

Randy Holmes-Farley said:
Your alk is fine, and the pH would not hurt to rise a lot (I wouldn't go above about pH 8.55), and in any case, you can boost alk with baking soda that won't raise pH.

So all the problems disappear, no matter what you do.

I see no chemical reason here for the RTN, but I'd stop adding soda water.

Is there a certain brand of baking soda you would recommend? I've read that table baking soda isn't very pure and could add unwanted elements. Also, what quantity and how often would you add. Maybe a recommended regime to get to and maintain the ALK at 8 or above?

Randy Holmes-Farley · Jan 12, 2024

emart805 said:
Is there a certain brand of baking soda you would recommend? I've read that table baking soda isn't very pure and could add unwanted elements. Also, what quantity and how often would you add. Maybe a recommended regime to get to and maintain the ALK at 8 or above?

Did you hear that from someone selling a branded product? An LFS, for example?

FWIW, many if not most branded alk supplements do not make any assertions about purity.

Food grade baking soda from a grocery store has purity limit guarantees, and I have never heard of anyone having a problem using it. MANY people here use it or products related to it (such as baked baking soda to give a pH boost as well)

This calculator shows how much is needed for any particular alk rise desired:

Reef Chemistry Calculator

Just dissolve the desired amount in some fresh water and add to a high flow area away from corals.

emart805 · Jan 12, 2024

Randy Holmes-Farley said:
Did you hear that from someone selling a branded product? An LFS, for example?

FWIW, many if not most branded alk supplements do not make any assertions about purity.

Food grade baking soda from a grocery store has purity limit guarantees, and I have never heard of anyone having a problem using it. MANY people here use it or products related to it (such as baked baking soda to give a pH boost as well)

This calculator shows how much is needed for any particular alk rise desired:

Reef Chemistry Calculator

Just dissolve the desired amount in some fresh water and add to a high flow area away from corals.

Yes, I heard it on BRS >.>. Of course, the thought crossed my mind that they were peddling their own product, but they made is sound so convincing. Thanks again!!

Randy Holmes-Farley · Jan 12, 2024

emart805 said:
Yes, I heard it on BRS >.>. Of course, the thought crossed my mind that they were peddling their own product, but they made is sound so convincing. Thanks again!!

lol

You're welcome.

They use USP pharmaceutical grade sodium carbonate. It may sound good in advertising, but I'd be interested to see them justify a claim that it was better in some way than FCC food grade sodium bicarbonate. From what I can see in the specifications, FCC grade is at least as good and has more specifications.

FCC food grade baking soda:

Food Grade Sodium Bicarbonate - Eti Soda

Food Grade Sodium Bicarbonate Food Grade Sodium Bicarbonate is used as an additive in the food production. Technical FeaturesSodium Bicarbonate also known as sodium hydrogen carbonate is a chemical substance white in colour and its aqueous solution is clear and […]

www.etisoda.com

NaHCO₃	%	99.3 min
Na₂CO₃	%	0.5 max
Cl⁻	mg / kg	250 max
SO₄⁻²	mg / kg	300 max
Water Insolubles	mg / kg	500 max
Pb / Lead	mg / kg	0.1 max
As / Arsenic	mg / kg	0.1 max
Hg / Mercury	mg / kg	0.1 max
Fe / Iron	mg / kg	10 max
Humidity	%	0.05 max
Solubility	g/100 ml water	15.6 (60°C) 9.55 (20 °C) 5.55 (0 °C)
pH	1 % solution	8.0 – 8.6