Maintaining Alk. What to do?

[bassking16]

Is it normal for dkh to be used up extremely fast compared to Calcium? My 75g mixed reef seems to be doing so. Within 6 or 7 days, my dkh reading went from 9 down to 5. Yet my Calcium stays right around 440, Magnesium stays at 1300, and my PH is steady at 8.3. SG stays at 1.025. Is this normal? What can I do to correct it. I do 15% weekly water changes, and have been dosing Tech CB DKH almost everyday trying to get it back up to a good level.
I plan on using Baking Soda from now on since I just found out that I could, and it is cheaper. How do I go about using the Baking Soda, and how do I mix it prior to dumping it into my sump return?
I plan on buying a drip dose setup from Live Aquaria. Can I dose the baking soda with that? I only ask because I have never heard of anyone dripping DKH. I've only heard of dripping Kalk?
I have a pretty good mix of SPS and LPS along with a few shrooms and zoas, so I know that it will get used up. I just thought that they levels of DKH and Calcium should be used up at the same pace.
Any insight would be greatly appreciated.
Thank You,
Bassking

[buffalo123]

Alk and calcium is a balancing act
give this a read
http://www.wetwebmedia.com/calcalkmar.htm

[Sk8r]

Your magnesium needs to be about 1280. WIthout it, your alk will start to sink, ditto the calcium.
'Dripping kalk' means topping off with ro/di with Mrs. Wages' Pickling Lime dissolved in it: just stir some into your topoff, and don't be too fussy about amounts: only the right amount can dissolve: only stir it once---you don't need a reactor or a stirrer, just a teaspoon---and don't let your pump sit down in the white gunk at the bottom: take only the filmy water. I run one---only have to intervene once a month. It simultaneously takes care of alk and cal---IF your magnesium is kept at a good level. But it will not raise alk and cal appreciably: you have to hand dose to get it where you want, THEN start your kalk topoff. It's a safe method: even a topoff accident doesn't flap a tank too much, just looks ugly and spikes the ph high briefly.

PS: if having trouble with alk, first be sure your test kit is accurate: you can get into trouble trying to chase a bad alk reading. Take some water to your store for a test, just to be sure.

[tmz]

Yes, Alkalinity often depletes more quickly than cacuium,. As biotic( growth of calcareous organisms) and abiotic precipitation occurs, 1 meq/l or 2.8 dkh of carbonate alkalinity is used for every 20ppm of calcium.

Baking soda can simply be mixed with ro water and poured in a high flow area of the tank . It's a good idea to keep jumps in alkalinity to 1 or less dkh per day. The calculator in the chemistry froum can help you figure how much you need.

Dripping alkalinity is a good practice, in my opinion.

BTW baking soda when baked turns to soda ash which has more carbonate and less bicarcarbonate. Consequently baked baking soda raises ph .

[bassking16]

Thank you for the replies. I really appreciate all the good info.

[Frick-n-Frags]

ALL biological activity produces acids which eat at your buffer reserve and ultimately your alk falls.

if there is life in the tank, the alk will always fall. that's life in the mini-reef.

and +1 on alk test double checking. i had a bad alk accident using 2 bogus test kits that both read high and read the same, then when everything bleached and died, i finally checked my 3.5meq water on a salifert from another reefer and it was 3dkh!!!! (it was a red sea and a seatest alk kits)

[tmz]

I don't think buffering capacity and alkalinity are quite the same thing.

The alkalinity we are concerned about is carbonate alkalinity (carbonate and bicarbonate which make up around 95% of the alkalinity in typical reef tanks). Carbonate is CO3;bicarbonate is HCO3.
CO2 from biological processes or the air increases carbonic acid which increases H+ and lowers ph. At higher H+ concentrations there is more bicarbonate relative to carbonate and thus less buffering capacity since there is less CO3 to take up H+. But the bicarbonate is still alkalinity and is used by calcareous organisms.

So you can have low ph(more acidic/more H+) and still have high alkalinity.

[Holyreefer]

bassking16,
i also just have started to dose baking soda in my tank due to my very low ALK
much cheaper than DKH Buffer and effective.
The hardest part is to keep it consistant

[JonnyD91]

Originally Posted by tmz

Yes, Alkalinity often depletes more quickly than cacuium,. As biotic( growth of calcareous organisms) and abiotic precipitation occurs, 1 meq/l or 2.8 dkh of carbonate alkalinity is used for every 20ppm of calcium.

Baking soda can simply be mixed with ro water and poured in a high flow area of the tank . It's a good idea to keep jumps in alkalinity to 1 or less dkh per day. The calculator in the chemistry froum can help you figure how much you need.

Dripping alkalinity is a good practice, in my opinion.

BTW baking soda when baked turns to soda ash which has more carbonate and less bicarcarbonate. Consequently baked baking soda raises ph .

So is it good to use soda Ash to raise alk?
Im using this now from BRS, i picked it up because they said it was the more popular recipe out of the 2.

[Holyreefer]

Originally Posted by JonnyD91

So is it good to use soda Ash to raise alk?
Im using this now from BRS, i picked it up because they said it was the more popular recipe out of the 2.

yes it is good to use Soda Ash (baking soda) it is a buffer
The BRS is good and what most people use for their 2/3 part solutions
And which recipe did you choose out of the 2 because each one will have their own effect on your tank in different ways PH etc...

[Untamed12]

Careful. Low Alk measurement often means that you just need to be adding more balanced Alk/Ca. There are exceptions where one might need to dose a bit of Alkalinity only...but high daily doses of Alk supplement only is probably not needed.

[rbnice1]

TGake the baking soda and put it on a cookie sheet for a hour in a oven at 425F. Then use it. I used to add 1 heaping table spoon to my sump every other day on my old 90 gallon tank.

[Chasmike]

New meaning to "Baking Soda" lol

[tmz]

Baked baking soda( soda ash) will raise ph noticeably since it is mostly sodium carbonate. the carbonate will absorb some H from the water. Unbaked baking soda may very slightly lower ph since it is sodium bicarbonate and contains an extra H proton.So it depends on your ph situation as to which you choose. Note typical sea water at 8.2 ph holds 110 parts bicarbonate : 20 parts carbonate.

[Frick-n-Frags]

there are several systems at play, but ultimately they are tied together.

my system is idling now, cooking out the last of the macro algae i used to keep. the alk still falls. i still have to add some baking soda even though not much is going on except for 1 fish and some algae in 100+ gallons. not even rampant coralline really. if there is life, the alk eventually falls. if i do 2-part, the Ca would go too high and funny stuff will grow on my heaters AND the alk will fall faster.

Anyway, this can explain why only alk falls and none of the other hard minerals do.

----------------
dripping baking soda - i combine it with makeup water in a dripper so it is quite dilute.
i like to drip baking soda in late afternoon. when baking soda hits, it temporarily wants to pull pH low like 7.8 w/e. then after a while it rises back up to 8.1. the natural peak pH time is the time i like. the reason i do not like sodium carbonate(baked baking soda) is the residual sodium is doubled per carbonate, so i will play around so i can just use baking soda.

[JeF4y]

Calcium reactor here...

And I end up adding magnesium to keep things stable. I know that my salt mix (red sea) is low on mg, so I add it to my water as it's brewing and all stays stable.

IIRC, mg should be 3x your Calcium.

[Holyreefer]

Ok i got my alk up "Finally" to 9.6!
I noticed yesterday that my acans were a lot more fuller so were my mushrooms so COOL!
THANK GOODNESS FOR BAKING SODA!
Now i want to just make sure i can keep it stable enough and then HERE I COME ACROS!
MILLIS...MUTLI COLOR...I CAN SEE YOU GUYS IN MY TANK NOW! LOL slowly of course but...EXCITED!