Bicarbonate

Yes, there ARE different grades of bicarb.

I don't know for sure, but suspect that "pool grade" bicarb will not be very pure (just gut feeling, as it does not have to comply with any specifications...)

I have been using "fit for human consumption" "Food grade" bicarb bought at any supermarket (currently using "Buffalo Brand") for many years. A purer grade would be "chemically pure" (CP), and the purest would be "analytical reagent" (AR), both grades only being obtainable from a chemical supplier.

I do believe that the "food grade" products are much purer (and cheaper) than the "pet grade" aquarium products sold by our petshops at hugely inflated prices. The AR grade is obviously *much* purer still, but also more expensive, costing nearly as much as the "petshop grade" products.

I do buy large quantities (5kg - 20kg) of CP and AR grade chemicals, such as magnesium chloride, calcium acetate and sodium carbonate, from an industrial supplier from time to time. If anyone would be interested, I could place a "bulk buy" order for these, and other, chemicals for our members... let me know if anyone would be interested.

Hennie

 

I'm in the same boat - I used to run a calcium reactor filled with coral "rubble", but stopped this some time ago due to pollutants in the coral media. I'm currently looking for some good quality reactor media, but until then will continue to use DIY chemical additives.

I would suggest the following (using it myself...):

Drip limewater (Kalkwasser), using "BP grade" (human medical grade) slaked lime, available at any chemist

Boost calcium as needed, using calcium chloride (CP grade, or better but more expensive AR grade, obtainable from a chemical supplier)

Balance the added calcium chloride by adding either normal or baked "food grade" sodium bicarbonate (koeksoda), obtainable from any supermarket. Bake, or use normally unbaked, depending on the pH of your water.

Further balance the ionic ratios by adding a mix of magnesium chloride CP grade or better, obtainable from a chemical supplier, and "BP grade" Epsom salt (magnesium sulphate).

A full recipe and details on mixing, etc. can be found here:

http://reefkeeping.com/issues/2006-02/rhf/index.php

Well, that would depend on your system's calcification rate. My corals use about 3dKH of alkalinity per week. With a total water volume of around 1000 litres, this results in approximately 12 teaspoons of baked bicarb and 130 grams of calcium chloride per week.

Hennie

 

Thanks for the info, Alan. No, I have not tried the Carribsea media. Where can I get this product? Also, how large are the particles?

Hennie

 

Hennie the media is Called CarribSea " Florida Crushed Coral "
Particle size ranges from 2-5mm.
I have been using it for the past 6 months and have been very happy.
As Alan has stated it dissolves fairly quickly, but with minimal impurities and quite a high strontium count. I'm also running the ZEO Mag in my reactor and keep Mag at 1250ppm without additional supplementation.

 

Oh Yes Aquality stocks it, speak to Liaquat.

 

Alan this my be a stupid question but why would you prefer to go through all the effort to do the dosing when you already have a Carx?

 

Hi, Guys

I am new to this hobby. Have tried it a couple of years ago in a 2ft tank fish only.
Know I have a 270L 10 weeks old, but already running into trouble. I have read this thread and looks like you guys know what you are talking about. What about some tips for a knew guy.

Jaco

 

Tx wil do so.

 

Hello Alan

For years now I have only been using Laboratory AR grade of any chemical I have used. The AR grade has very minimal contamination of impurities which are always listed on the bottle.

I find it very difficult to understand the amount of bi carb you use to maintain a dkh of +- 8. Do you use a calcium reactor?

I do a monthly dkh test and only have to dose 1-2 t/s per month for a dkh of + 9 I also use a calcium reactor which keeps thing up there even my carbonate hardness.

Perhaps you should try and use a laboratory grade bicarb it might make a differance or change your calcium reactor which should maintain calcium and dkh to a certain extent.

George

 

I agree, AR grade is guaranteed to contain certain tested limits of impurities. That is not to say that the CP grade is less pure, it's just not proven to be as pure...

Raising the dkh of a 1000 liters of water from 7.0 to 8.0 would require about 5 teaspoons of sodium bicarbonate, or 3 teaspoons of sodium carbonate. A healthy tank containing lots of growing hard corals could easily have a demand of 2 dkh per week, so an addition of 10-12 teaspoons of bicarb is not out of the ordinary.

I don't think the purity grade would make much differance to the "strength" of the bicarbonate - the water contained within the crystalline structure would - not sure if bicarb has crystalline water, though (CaCL2 has, and can be obtained as either anhidrous, di-hydrate or hepta-hydrate, if memory serves)... Chemical Gurus, HELP...

Hennie

 

Man you boys know your stuff - I got lots and lots to learn!

I have a 500l tank and battle to keep a DKH of 8-9 I have been using reefbuilder but seem to have to add alot and it never seems to get higher than 7.....

 

Hello Hennie

The Grade would most definitely not make any difference to the kh outcome, but the accumulation of impurities would affect the tank as a whole ( naturally this takes time)
so by using the best possible grade you actually help the tank.

George

 

The lab I used to work at packed all the chemcials for Saarchem (and later MErck as well).

Both CP and AR grades came out of the same bag. The only difference was that the AR grade was tested to ensure it met all the specs before being packed.

It was extremely rare that one of their chemcials did not meet the AR spec and could only be used for CP.

So if you are buying lab chemicals, you can with a high degree of confidence purchase a CP grade from a reputable supplier like Merck instead of spending the extra on AR grade.