How to raise KH without affecting PH

[my name is mike]

Hi, I have a 20 gal that completed it's cycle about a month ago. All my parameters are good, except KH which is hanging around 6 or 7. I have read about dosing baking soda to raise KH without affecting PH , but some sources say that it will.

 

RO/DI water only

SG - 1.026

Temp - 80

KH - 6 - 7

PH - 8.2 - 8.4

Calcium - 480

Nitrate - 0

Nitrite - 0

Ammonia - 0

Phos - 0

RO/DI for top off (no kalk and no buffer, except for twice when i used Seachem Reef Buffer, but it raised both PH and KH so i quit).

 

Should i just let the tank fully mature and see where it all ends up or is there something i can/should dose to avoid any adverse effects?

 

The tank is not really stocked yet, except for CUC of a few snails and hermits, and a cluster of red mushrooms. i do not plan on adding anything else any time soon.

 

Thanks, Mike

[vangvace]

baking soda and baked baking soda both have an effect on pH, but the proper ratio of both mixed to a pH of 8.2. If you do a search you should find an old post by me covering it in more detail.

[reefdan]

dosing straight baking soda doesn't lower it much. i would just go that route

 

EDIT: i stand corrected by fosi

[Mr. Fosi]

Actually baking soda (sodium bicarbonate, NaHCO₃) lowers pH just after you add it.

 

Since your pH is high use NaHCO₃.

 

- measure out ~1 1/8 cups (297 g) of NaHCO₃ into a 1 gal container

- add enough RO/DI water to make the solution 1 gal

- mix thouroughly (may take a while and it goes quicker if you use warm/hot water)

 

Then go to a good reef chemistry calculator, put in your system volume, your current alk, your desired alk and tell it you are using "Randy's Recipe 2 Alkalinity". Let the model do its thing and it'll spit out how much NaHCO₃ solution you need to add to get your alk where you want it.

[my name is mike]

thanks everyone ! -- i did not realize it would lower it a bit (which I'm fine with since i tested last night at a ph of 8.4) -- that calculator is a god send -- thanks so much

 

Fosi, i am about to set up an auto top off system for my tank and was wondering if i should add some baking soda to my top off (essentially making a randy's recipe, or a watered down version) -- or do people generally prefer to test, dose, and test again opposed to dosing automatically (i think i know my answer now that i type it -- ha!)

 

thanks again everyone, this site has been very helpful

[Mr. Fosi]

... i am about to set up an auto top off system for my tank and was wondering if i should add some baking soda to my top off (essentially making a randy's recipe, or a watered down version) -- or do people generally prefer to test, dose, and test again opposed to dosing automatically...

 

You can do it either way depending on what level of risk you are willing to tolerate and how much time you want to spend on testing/dosing.

 

I strongly recommend that you spend a couple weeks testing your Ca/Alk daily before dosing and keep a record of what your daily numbers are and what volume(s) of additives you dosed. This will help you get a handle on approximately what dose volume you need each day to maintain your parameters within a given range. Test only once a day, especially for Ca since it takes a minimum of several hours before it will correctly register on your test kit.

 

Once you have done this dose volume analysis, I recommend that you either use that data to calculate how much Ca/Alk your system uses every day or skip a dose/test combo and let the system draw them down for 48 hours before testing/dosing again.

 

Either way you get an estimate how much Ca/Alk your system currently uses.

 

If you couple that with an estimate of what volume of topoff you go through a day, you could do the calculations to determine what concentration you need in your topoff to maintain your levels. This is risky, however because while the concentatrion of the topoff won't change, the amount of topoff you add to the tank almost certainly will. This could lead to alternate under or overdoses.

 

Personally, I dose every day because my system uses a lot of Ca/Alk/Mg. I spent 2.5 weeks doing daily tests to get a feel for what I am doing and because I did that, I don't need to test as often... I now test once a week before my waterchange.

 

Each day I add 15-20 mL of Ca, 15 mL alk and 10-20 mL Mg; I am using the BRS Recipe 1, 2-part kit and a couple ESV B-Ionic dosing cups.

[my name is mike]

Totally makes sense - thanks for the detailed explanation.

 

On an unrelated note, go cocks! I went to USC as well.

[The Propagator]

Actually baking soda (sodium bicarbonate, NaHCO₃) lowers pH just after you add it.

 

Since your pH is high use NaHCO₃.

 

- measure out ~1 1/8 cups (297 g) of NaHCO₃ into a 1 gal container

- add enough RO/DI water to make the solution 1 gal

- mix thouroughly (may take a while and it goes quicker if you use warm/hot water)

 

Then go to a good reef chemistry calculator, put in your system volume, your current alk, your desired alk and tell it you are using "Randy's Recipe 2 Alkalinity". Let the model do its thing and it'll spit out how much NaHCO₃ solution you need to add to get your alk where you want it.

 

Less then 10-12 hours after you add the baking soda solution and your PH is back to what it was though ( in my systems it is any way ). I use it regularly my self and have never had a problem. If you are worried about a minimal drop or you need to add such an amount that will cause a maximum drop then simply split your dosage up in to two days, or space them out 8 hours apart or so.

[Osaka-san]

Is it just me or have you noticed USC and cocks always tied together? And I thought it was the University of Spoiled CHILDREN! Oh wait - South Carolina - well by all means - Go Cocks!

[The Propagator]

I think you two just like saying cocks.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Osaka-san]

Could be - or maybe I couldnt resist a dis to to the mighty condoms. Sorry. I'll try to stay on topic hereafter. Never use a big word where a diminutive one will suffice. Speaking of USC and deminutive...

[The Propagator]

[my name is mike]

ha! --

 

i have started to dose the baking soda and it works -- i have raised it a bit and need to start dosing more to get it where i really want it -- but i wanted to start slow

 

on a related note, i had always been checking PH after my lights had been on a while, this morning however i checked it after a night of lights off and it was down to 7.8. I knew that PH fluctuated from day to night (and you could help curb that with a fuge, which i dont have and dont have room for) but is a swing from 7.8 to 8.2 too much or typical ?

 

i ask because i got my first fish yesterday afternoon (a tailspot blenny) and he is looking a bit stressed still (color splotches and not moving out of his hiding place) -- thats why i tested the water this morning to make sure it wasnt water parameters -- the only abnormal thing was the low PH -- i did get him to eat a bit, and i know thats a good sign - maybe the little guy just needs a minute to adjust.

 

thanks, mike

[Mr. Fosi]

... is a swing from 7.8 to 8.2 too much or typical ?

 

It's typical.

 

... maybe the little guy just needs a minute to adjust.

 

That's my guess.