Dosing Alkalinity.

[mlopezk8]

I have a question my alkalinity dropped from 8.4 DKH to 7.6 DKH with in 4 days because I was trying to up the calcium to 430 so I was dosing more Calcium so my Alkalinity dropped So my question is I used the BRS calculator so I could bring DKH back up to 8.5 calculator says to add 51 ml of soda ash do I add it all at once or do I add the amount to my daily dosing I dose currently 13 ml 8 x a day total

 

[Lasse]

All changes should be gradually and small. I would rise my daily dosage slowly. Calculate for around 10 days. But be aware that you have to rise the dosage for this 10 day a little bit more than your calculations because your higher consumption (compared with the time before you Ca addition) will consume some alkalinity too. Make some measurements in order to check that you on the right track. When you have reached your desired alkalinity - just get back to the old settings plus a little bit more. Try to balance the Ca and alkalinity dosing.

Sincerely Lasse

 

[Randy Holmes-Farley Verified Community Expert]

I have a question my alkalinity dropped from 8.4 DKH to 7.6 DKH with in 4 days because I was trying to up the calcium to 430

Just to clarify, I don't think it dropped "because" you were raising calcium. It dropped because various processes in reef tanks consume alkalinity regularly. You should expect continued drops and the need to boost alkalinity regularly.

 

[madweazl]

With such a small delta (< 1 dKh), I wouldnt hesitate to make the correction in one day but you can certainly do it slower. Are you dosing 13ml total per day or 104ml (13ml x 8 doses)? If it's 13ml per day, this suggests your tank is consuming .2 dKh per day (provided you didn't decrease alkalinity dosing when you increased calcium dosing). You can use the dosing calculator to increase your daily dose to offset that consumption rate and make 1 (or more) manual corrections (i.e. you dosing alkalinity directly to offset the delta). You can also do as Lasse suggests and increase your daily total dose to make up that delta gradually over time.

 

[mlopezk8]

With such a small delta (< 1 dKh), I wouldnt hesitate to make the correction in one day but you can certainly do it slower. Are you dosing 13ml total per day or 104ml (13ml x 8 doses)? If it's 13ml per day, this suggests your tank is consuming .2 dKh per day (provided you didn't decrease alkalinity dosing when you increased calcium dosing). You can use the dosing calculator to increase your daily dose to offset that consumption rate and make 1 (or more) manual corrections (i.e. you dosing alkalinity directly to offset the delta). You can also do as Lasse suggests and increase your daily total dose to make up that delta gradually over time.

Thank you for responding The dosing of Alkalinity per day is 104 ml 13 ml 8x throughout the day .

 

[mlopezk8]

All changes should be gradually and small. I would rise my daily dosage slowly. Calculate for around 10 days. But be aware that you have to rise the dosage for this 10 day a little bit more than your calculations because your higher consumption (compared with the time before you Ca addition) will consume some alkalinity too. Make some measurements in order to check that you on the right track. When you have reached your desired alkalinity - just get back to the old settings plus a little bit more. Try to balance the Ca and alkalinity dosing.

Sincerely Lasse

Ok I will dose a little at a time until I reach my desired alkalinity then dose same amounts of cal.and alk. Thank you .

 

[ReefKeeperElite]

Make sure your Magnesium level is sufficiently high, otherwise trying to balance Alk and Ca is difficult. I keep mine at 1400. To me that is the first thing to do before any other adjustments.

 

[blasterman]

Yeah...mag that drifts down around 1000 really makes things unstable, especially calcium.

I've found that raising alk 1 dKH at once isnt a big deal. It's more important to get to your cruise point. I have a gimpy doser on one of my heavy SPS tanks that will go from 9 to 6.5 dKH in 24 hours if it's not working. Tank is seriously over loaded. I use raw baking soda to get it back up and montipora and LPS dont give a flip about the alk spike. Acropora on the other hand arent thrilled, so they went to another tank.

 

[mlopezk8]

Make sure your Magnesium level is sufficiently high, otherwise trying to balance Alk and Ca is difficult. I keep mine at 1400. To me that is the first thing to do before any other adjustments.

My Magnesium Levels are 1320 At the moment .