Alk consumption

[Scubapro13]

I am dosing 80 ml of soda ash and its still needs more. I have a jbj 30 and that seems high for a small tank. I have 10 sps frags in the with a durasa clam( clam is doing well) can't get alk stable and it seems like I'm missing something. Calcium is at 460 mag is around 1400

 

[Dr. Reef Verified Sponsor]

what level of Alk are you trying to keep? how much does it drop daily?
how much soda ash did you mix in 1 gal rodi water?

 

[Scubapro13]

I'm trying to keep it at 8.5 ideally but it keeps dropping to like 6.5 even,with the high dose. I'm using the new be a pouch that you mix to 1 gallon

 

[Scubapro13]

Its weird it seemed like i was just starting to get it then it dropped and now i can't keep it up. The only thing I have changed lately is adding some gfo and increasing flow

 

[Dr. Reef Verified Sponsor]

how are you measuring alk? its not strange for an established tank to drop 2-3 dkh per day.

 

[Scubapro13]

Hanna checker twice a day right now

 

[Scubapro13]

But I'm dosing every hour with dosing pump with 80 ml and its still a losing battle

 

[Scubapro13]

Also cleaning tank today I have a section of sand that has turned solid

 

[Stigigemla]

I believe 1 of Your values is wrong and You are precipitating kalcium carbonate.
I suppose one of Your tests is out. Which brand do You use?

 

[Randy Holmes-Farley Verified Community Expert]

When you have precipitation the ways to deal with it are to:

1. Temporarily ( a week) let the alkalinity and pH drop by maintaining 7 dKH only, and use baking soda, not sodium carbonate (soda ash).

2, Do not use phosphate binders, especially GFO.

3. Do not use organic binders such as GAC and Purigen.

 

[hart24601]

The sand is a good indicator of your problem being precipitation. The good doctor's advise above should drastically help.

 

[Scubapro13]

I believe 1 of Your values is wrong and You are precipitating kalcium carbonate.
I suppose one of Your tests is out. Which brand do You use?

I'm using red sea test kits for calcium and magnesium. Hanna checker for alk

 

[Scubapro13]

When you have precipitation the ways to deal with it are to:

1. Temporarily ( a week) let the alkalinity and pH drop by maintaining 7 dKH only, and use baking soda, not sodium carbonate (soda ash).

2, Do not use phosphate binders, especially GFO.

3. Do not use organic binders such as GAC and Purigen.

How do I dose the baking soda?

 

[Randy Holmes-Farley Verified Community Expert]

How do I dose the baking soda?

Same as any other solid alk additive: dissolve it in fresh water and dose it.

If you use my DIY recipe, then you can use some of the online calculators available to determine needed doses to get a particular alk boost:

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2006-02/rhf/index.php

Recipe #2, Part 2: The Alkalinity Part

Dissolve 297 grams of baking soda (about 1 1/8 cups) in enough water to make 1 gallon total. This dissolution may require a fair amount of mixing. Warming it speeds dissolution. This solution will contain about 950 meq/L of alkalinity (2660 dKH). As mentioned earlier, Arm & Hammer is a fine brand of baking soda to use in these recipes. Be sure to NOT use baking powder. Baking powder is a different material that often has phosphate as a main ingredient.

A suitable calculator, enter Randy's recipe 2:

http://reef.diesyst.com/chemcalc/chem_calc3.html

 

[miniChou]

What's your salinity? I had a similar issue as you when my salinity got too low.

 

[braappn]

Randy, when a person is having this issue (sand solidifying) and they switch to regular baking soda to rectify it, do they generally switch back to soda ash once the cycle of precipitation is broken, or do they stick with the baking soda going forward?

I was having the same problem as the OP and followed your suggestion above to stop it. It was successful and I am still dosing the bicarbonate months later.

Thank you and good luck to the OP. Beware that I did hurt a few corals by allowing alk to drop too far during the reduced dosing period. If Randy believes keeping it at 7 with baking soda will be effective I’d certainly stick with that. Mine fell into the 5s and had some negative effects on corals.

 

[Randy Holmes-Farley Verified Community Expert]

Randy, when a person is having this issue (sand solidifying) and they switch to regular baking soda to rectify it, do they generally switch back to soda ash once the cycle of precipitation is broken, or do they stick with the baking soda going forward?

I was having the same problem as the OP and followed your suggestion above to stop it. It was successful and I am still dosing the bicarbonate months later.

Thank you and good luck to the OP. Beware that I did hurt a few corals by allowing alk to drop too far during the reduced dosing period. If Randy believes keeping it at 7 with baking soda will be effective I’d certainly stick with that. Mine fell into the 5s and had some negative effects on corals.

The only advantage of soda ash (sodium carbonate) is higher pH. Higher pH has advantages, especially if it tends to be low in the aquarium. But it also accelerates precipitation.

Precipitation tends to happen fastest onto existing, bare calcium carbonate surfaces. Many times, slowing down precipitation and waiting for the new bare calcium carbonate to get coated with organics, magnesium, phosphate, bacteria, etc, will then allow you to raise alkalinity and pH back to levels you might prefer, with less risk of more precipitation.

If you want to raise alk and pH, waiting longer than a few weeks isn't changing much and it is ready to go higher again, if you want.

 

[timrocks311]

I have this same issue going on. I have a 4 month old 40 gallon with dry rock. I only have a few LPS and zoa frags and my ALK drops quickly. Randy previously advised that I only try to maintain 7 dkh which is what i'm trying to do, but daily I'll see it drop to 6.6 dkh. I'll dose up to 7.2 or so and it still drops. I've been trying kalk in my ATO to help maintain it but that doesn't seem to be working either. Calcium and Mag have been steady and pH has been 8.2-8.4 consistently.

I guess it is precipitating out on the rocks and sand. I don't have coraline algae yet. I'm going to try the baking soda. I already do not run GAC or GFO.