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Chicken/egg problem for Alk/Ca/PH?
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@Randy Holmes-Farley
So looks like stability is alluding me. Morning Alk down to 7.2dKH.
I'll continue to increase Kalk dosing to 2.25ml/min or roughly .75dKh replacement.
Should I take other measures? I kinda feel like I'm missing something.
So looks like stability is alluding me. Morning Alk down to 7.2dKH.
I'll continue to increase Kalk dosing to 2.25ml/min or roughly .75dKh replacement.
Should I take other measures? I kinda feel like I'm missing something.
Randy Holmes-Farley
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Higher pH increases alk demand, and 0.75 dKh per day may not be meeting it.
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Randy Holmes-Farley
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If pH is where you want it, then maybe use baking soda for that alk increase.
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Yeah. pH is great. I'll try that....
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So I used baking soda for a .1dKH twice and left my Kalk at .7dKH replacement.
I'm now back to 7.6dKH. I guess I'm still trying to get to steady state and stability. I feel I'm close.
Did a quick PO4 and NO3 check and PO4 has bottomed out again and NO3 is still locked in at 25ppm.
I'm not sure I buy 0 PO4 as I'm getting algae film on glass and fuge with increase lighting and schedule is seeing a little Marco and nuisance algae growing.
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So stability is still eluding me. How frustrating. I had another sudden .9dKH drop over 36hrs. After seeing steady values the previous 36hrs.
I'm dosing .7dKH....so seemingly I'm .6dKH short per 24hr.
I've raised the dosing to 1dKH and will continue to watch the trend and probably bump it to 1.5 dKH next if trend continues...
@Randy Holmes-Farley Since I'm at 7dKH now, should I Just bump the Kalk more now as 7dKH will slow consumption?
I'm dosing .7dKH....so seemingly I'm .6dKH short per 24hr.
I've raised the dosing to 1dKH and will continue to watch the trend and probably bump it to 1.5 dKH next if trend continues...
@Randy Holmes-Farley Since I'm at 7dKH now, should I Just bump the Kalk more now as 7dKH will slow consumption?
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Are you sure? pH is getting to 8.36. Is a swing this large ok?
I actually built an air solenoid to automate cycling between CO2 scrubbed air to my CO2 heavy house air.
@Randy Holmes-Farley Yes...too effective is possible, I just hit 8.53 pH and rising.
Long story short, I wanted to have better control over my CO2 scrubbing and decided to switch to a DC skimmer that I could easily tune and make recirculating.
Enter the Aeraqua Duo. I didn't expect this to be so effective. It can move so much air, that I can drive up or down my pH fairly quickly. I'm now experimenting with its setting and having a solenoid air valve controlling the source of the air (scrubber or house air).
Imagine a skimmer / CO2 scrubber for pH control. It may or may not work... I hope with this control I can lock in my pH to a fairly tight range.
Hi Guys, from my experience, when you dosing kalk, you have to dose it to a very high flow place, like the center of your power head. If there is not enough HCO3- in that area, CA(OH) will become CA2CO3, which will cause low CA- and low ALK.
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@Randy Holmes-Farley Riddle me this...
With 3ml/min Kalkwasser dosing I'm now getting increasing pH without skimmer and scrubber. My skimmer / CO2 scrubber pH controller is coming on to reduce the pH.
For my 410 L tank/sump volume, I am adding 3600ml of Kalkwasser which seems to be my evaporation rate. Per my calculation, I am adding about 1dKH and roughly 0.5 - 0.6 pH increase per day.
Since my normal dKH w/out Kalk, Skimmer, or CO2 Scrubber is 7.8-7.9, I may no longer need a CO2 scrubber to bring up pH (at least during the day).
I'm not sure what is consuming the Alk as the tank is only ~4 months old and I really don't see much growth on frags or coralline algae.
If demand goes up, I guess I'm looking to start dosing All-for-Reef or DIY 2-part.
I really think focussing initially on getting a good and steady pH unlocked my Alk consumption via Kalk which is a feedback loop for a stable near ocean parameter pH.
Or are you betting on abiotic precipitation and I'm overdosing Kalk?
With 3ml/min Kalkwasser dosing I'm now getting increasing pH without skimmer and scrubber. My skimmer / CO2 scrubber pH controller is coming on to reduce the pH.
For my 410 L tank/sump volume, I am adding 3600ml of Kalkwasser which seems to be my evaporation rate. Per my calculation, I am adding about 1dKH and roughly 0.5 - 0.6 pH increase per day.
Since my normal dKH w/out Kalk, Skimmer, or CO2 Scrubber is 7.8-7.9, I may no longer need a CO2 scrubber to bring up pH (at least during the day).
I'm not sure what is consuming the Alk as the tank is only ~4 months old and I really don't see much growth on frags or coralline algae.
If demand goes up, I guess I'm looking to start dosing All-for-Reef or DIY 2-part.
I really think focussing initially on getting a good and steady pH unlocked my Alk consumption via Kalk which is a feedback loop for a stable near ocean parameter pH.
Or are you betting on abiotic precipitation and I'm overdosing Kalk?
Randy Holmes-Farley
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FWIW, your pH increase seems unusually large for that amount of limewater. Even added all at once, when I added 1.4 dKH worth of hydroxide to new salt water, I only saw that same amount of rise, and when spread out, I'd expect a much smaller boost. Maybe other factors are at play in getting to the 0,5 to 0.6 pH units.
Abiotic precipitation may be likely. We have no clear understanding of how large it is in most reef tanks, even if it goes largely unseen.
Abiotic precipitation may be likely. We have no clear understanding of how large it is in most reef tanks, even if it goes largely unseen.
blitzkragz
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If you are doing auto water changes with Tropic Marin Pro, that will suppress your alk. When the pandemic hit and TMP was out of stock I switched to regular IO and the increase in alk was significant.
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It's a riddle I can't seem to figure out. Maybe time to recalibrate equipment again.
pH drifted up all day and triggered the skimmer without CO2 scrubber 4 times to reduce the pH.
pH initially drifted down at 12:15am and triggered the skimmer with CO2 scrubber to raise the pH. It ran once for 2hrs all night as the pH stayed rather stable.
Maybe I should run another cup aeration test. We are in spring and my house CO2 dynamics may be different with the warmer weather.
What else can I try? The numbers and consumption don't make sense and I'm struggling to find stability.
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It's being dosed to the return of my sump which includes an additional powerhead. I'd say 500-600 gallons per hour in a 5 gal space....so I think it should be ok.
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My AWC is 1% daily which should only have a very minor effect that probably can't be observed on the daily level.
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Ran cup test next to tank and pH settled at 7.9. So I don't think house CO2 has changed all that much.
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One more observation is that when my kalk pauses dosing to mix and settle for an hour, the pH drops by 0.02 in about 30 minutes...which triggers the skimmer and CO2 scrubber.
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For those following along, my Alk has started to drift up again. I've gone from a low of 6.8 to 7.8 in the last 5 days. The only change in the tank has been locking in the pH and stopping carbon dosing. I stopped the carbon dosing to see if there would be any changes in the tank with respect to NO3 which has been locked in at 25ppm despite the carbon dosing and minimizing inputs. I'm using the Nyos Zero and don't feel like it's done anything...so seeing what temp stopping will result in.
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