Determining rate of alk depletion

CeeGee · 12/03/2008, 09:45 PM

I have had my tank pretty steady for a long time but my alk fluctuates a little more than I would like since I lost a few corals due to this horrendous algae outbreak that I have been battling for the last couple of months. The algae battle is starting to work (although it is going slow) due to the use of a carbon/bac system I have employed.

It has been a long time since I have determined how much alk I use per day. I was thinking that I could take a alk reading tonight at 7 (already done that) and not add any 2 part and take another alk test in the morning at 7 before I leave for work. Figure out the difference between the two rating multiply it by two and then use the alk/calcium calculator to determine exactly how much b-ionic I should adding daily.

Anyone see any loopholes in this and if so what would be a better way to determine this?

Thanks for your help,
C.G.

mg426 · 12/03/2008, 09:52 PM

I dosed my system to 11DKH then added no Alk for three days. I divided the amount used by three then used the calculator to figure out how much to get back to 10DKH. I now dose the same amount every day and my Alk stays right around 10 DKH (measured a couploe hrs) after dosing. Same thing you are doing ,I just went with a longer time sample.

CeeGee · 12/03/2008, 09:54 PM

I would do something like that but since I am using a carbon/bac system alk is pretty dang important so that I don't melt my SPS.

I figured 12 hours should tell me something or another. I was unsure though if lights being off or anything of that nature would affect readings and make the test unreliable.

seapug · 12/03/2008, 10:19 PM

Wait 24 hours so your tank goes through a complete light cycle. Alkalinity and Calcium depletion rates will vary based on pH and water quality parameters that shift throughout your light and dark cycles.

spleify · 12/03/2008, 10:48 PM

I am an advocate of the slow method. I determined my starting point, I chose an amount to dose, Dosed that amount for 2 weeks, then tested again. Determined I needed more, brought my alk back up to desired level, dosed for two weeks, tested. Once again determined I need to increase again. Raised once again, dosed, tested. Finally found my tanks consumption!

Now I realize this method is probably not what you (or many people) are looking for, but I found it to be the most true method.

HTH

Spleify

CeeGee · 12/03/2008, 10:54 PM

Quote:

Originally posted by seapug
Wait 24 hours so your tank goes through a complete light cycle. Alkalinity and Calcium depletion rates will vary based on pH and water quality parameters that shift throughout your light and dark cycles.

Will do. Thanks that is exactly what I needed to know.

crvz · 12/04/2008, 07:59 AM

I'd also do this a couple times. Wait 24 hours, test, then dose to get it back. A few days later, do it again. You'll want more than 1 data point to get an accurate measure of actual alk need.

12/03/2008, 09:45 PM	#1
CeeGee Registered Member Join Date: Jun 2002 Location: TN Posts: 3,272	Determining rate of alk depletion I have had my tank pretty steady for a long time but my alk fluctuates a little more than I would like since I lost a few corals due to this horrendous algae outbreak that I have been battling for the last couple of months. The algae battle is starting to work (although it is going slow) due to the use of a carbon/bac system I have employed. It has been a long time since I have determined how much alk I use per day. I was thinking that I could take a alk reading tonight at 7 (already done that) and not add any 2 part and take another alk test in the morning at 7 before I leave for work. Figure out the difference between the two rating multiply it by two and then use the alk/calcium calculator to determine exactly how much b-ionic I should adding daily. Anyone see any loopholes in this and if so what would be a better way to determine this? Thanks for your help, C.G.

12/03/2008, 09:52 PM	#2
mg426 Registered Member Join Date: Jan 2006 Location: maryland Posts: 6,923	I dosed my system to 11DKH then added no Alk for three days. I divided the amount used by three then used the calculator to figure out how much to get back to 10DKH. I now dose the same amount every day and my Alk stays right around 10 DKH (measured a couploe hrs) after dosing. Same thing you are doing ,I just went with a longer time sample. __________________ I found a way to make a small fortune running a reef tank. Start with a large fortune. Unofficial President of the SEACLONE haters club Current Tank Info: 125 mixed reef 110 lbs LR, 1x250watt XM 20K MH 2x175watt XM 20K MH on Magetics 2X96 watt actinic PC, 220 watt VHO actinic, 30 gallon refugium, closed loop system powered by Sequence Dart MSX 200 skimmer 38 gallon sump, Oceansmotions squirt

12/03/2008, 09:54 PM	#3
CeeGee Registered Member Join Date: Jun 2002 Location: TN Posts: 3,272	I would do something like that but since I am using a carbon/bac system alk is pretty dang important so that I don't melt my SPS. I figured 12 hours should tell me something or another. I was unsure though if lights being off or anything of that nature would affect readings and make the test unreliable. __________________ My algae WAS special. Current Tank Info: 75 gallon display, 40 gallon breeder sump, RLSS R6i, ATI Powermodule, Apex, Ecotech MP40's

12/03/2008, 10:19 PM	#4
seapug Registered Member Join Date: Dec 2006 Location: 4980 ft. Posts: 7,954 Blog Entries: 1	Wait 24 hours so your tank goes through a complete light cycle. Alkalinity and Calcium depletion rates will vary based on pH and water quality parameters that shift throughout your light and dark cycles. __________________ insert clever saying here. Current Tank Info: 200 gallon custom Marineland DD peninsular tank. LPS dominated mixed reef. Previous 90 gallon mixed reef TOTM April 2009.

12/03/2008, 10:48 PM	#5
spleify Registered Member Join Date: Dec 2003 Location: Denver, Colorado Posts: 9,579	I am an advocate of the slow method. I determined my starting point, I chose an amount to dose, Dosed that amount for 2 weeks, then tested again. Determined I needed more, brought my alk back up to desired level, dosed for two weeks, tested. Once again determined I need to increase again. Raised once again, dosed, tested. Finally found my tanks consumption! Now I realize this method is probably not what you (or many people) are looking for, but I found it to be the most true method. HTH Spleify __________________ Make it a Great Day!!!! Current Tank Info: 60 gal SPS cube, with 25 gal refugium, 400W MH, DIY Lumenarc III, DIY skimmer, DIY stand and canopy. 40 breeder LPS with 40 gallon sump, DIY stand, 250W MH

12/04/2008, 07:59 AM	#7
crvz Team RC Member Join Date: Jul 2005 Location: houstonia Posts: 7,989	I'd also do this a couple times. Wait 24 hours, test, then dose to get it back. A few days later, do it again. You'll want more than 1 data point to get an accurate measure of actual alk need. __________________ -Chris- You don't win friends with salad. "Look! They're trying to learn for free!" ... "Use your phony guns as clubs!" Current Tank Info: rectangluar? wet?