Maintaining alkalinity (new dosing pump)

[Wet_Fretboards]

Hello,

I have a reefer 170 with an estimated actual volume of about 38 gallons. There is 1 three headed duncan (4 if you count the baby), a 1" toadstool leather, quite a few zoas, and some clam type thing that hitched a ride, and is thriving, and 0 coraline. I recently purchased a neptune DOS to dose alk and Ca, because I became tired of dealing with kalk in the ATO. My Dkh seems to drop throughout the day, as does the PH. Calcium seems to be well managed. I'm using ESV B-ionic for both. I'm currently dosing 30 ml of alk over 24 hrs in .4 ml doses every 19 minutes. Is it common for DKH to drop that much with so few inhabitants? I was manually dosing until now, but I want to avoid swings, and become more stable before I add expensive frags.
Current parameters
Temp 77.6
Salt 35 ppt
PH 8.11
Ca 4300
Mg 1380
Dkh 9.5 ( I just added a boost from 8.2)
No3 2.5
Po4 .02


I run carbon and GFO. Protein skimmer. No refugium. Reefrock 2.0, CarribSea special grade about 1 inch deep, give or take.

 

[chipmunkofdoom2]

Have you tested for magnesium? Mg prevents calcium and carbonate from precipitating out of solution. If your Mg is not sufficiently high, precipitation could result, meaning you need to dose more to maintain your calcium and carbonate alkalinity levels.

GFO can also cause precipitation of calcium carbonate (see the obligatory Randy Holmes-Farley article).

As an aside, how long did it take you to go from 8.2 dKh to 9.5 dKh? Though soft corals and LPS may not mind that much of an increase, for an SPS that might be a stressful increase unless it was done over time. Personally, I wouldn't try to raise my carbonate alkalinity by more than 0.5 dKh per day.

 

[Randy Holmes-Farley Verified Community Expert]

Hello,

I have a reefer 170 with an estimated actual volume of about 38 gallons. There is 1 three headed duncan (4 if you count the baby), a 1" toadstool leather, quite a few zoas, and some clam type thing that hitched a ride, and is thriving, and 0 coraline. I recently purchased a neptune DOS to dose alk and Ca, because I became tired of dealing with kalk in the ATO. My Dkh seems to drop throughout the day, as does the PH. Calcium seems to be well managed. I'm using ESV B-ionic for both. I'm currently dosing 30 ml of alk over 24 hrs in .4 ml doses every 19 minutes. Is it common for DKH to drop that much with so few inhabitants?
.

That's a drop of 1.8 dKH per day. That's not that high and can happen in even a soft coral only tank. Coralline algae uses a lot, as do other organisms and abiotic processes.

If you let the alk drop a bit, the daily demand will be lower.

 

[Wet_Fretboards]

Went back and edited. Mg is 1380. I upped the alk very slowly. Id say over 18 hours or so. I've read that no more than 1.4 dkh should be fine in 24 hours. Didn't know about the gfo thing. Off to find that article now. Thanks.

 

[Wet_Fretboards]

That's a drop of 1.8 dKH per day. That's not that high and can happen in even a soft coral only tank. Coralline algae uses a lot, as do other organisms and abiotic processes.

If you let the alk drop a bit, the daily demand will be lower.

Ok. I feel a little better now. Just want to dial this doser in so that it stays around 10. I don't want to have to boost it daily, as my whole objective is to avoid swings in Ph and DKh.

 

[Wet_Fretboards]

What worries me most is that my PH is steadily dropping now. With the kalk in the ato, it didn't drop so far. It's already down to 8.09 as i write this. I have my skimmer intake plumbed to outdoors, and decent surface agitation.

 

[Cory]

What worries me most is that my PH is steadily dropping now. With the kalk in the ato, it didn't drop so far. It's already down to 8.09 as i write this. I have my skimmer intake plumbed to outdoors, and decent surface agitation.

Kalk raises ph a lot as it uses co2. Two part can raise ph depending on which your using. One lowers it slighly and the other raises it.

 

[Killer Karma]

I have a 350 gallon tank with a pretty good amount of corals and im only dosing about 30ml a day. I agree you should check your Mg.

 

[Wet_Fretboards]

I have a 350 gallon tank with a pretty good amount of corals and im only dosing about 30ml a day. I agree you should check your Mg.

1380 with red sea Mg pro

 

[Randy Holmes-Farley Verified Community Expert]

Ok. I feel a little better now. Just want to dial this doser in so that it stays around 10. I don't want to have to boost it daily, as my whole objective is to avoid swings in Ph and DKh.

Expect to have to dose daily in most established reef tanks.

 

[Randy Holmes-Farley Verified Community Expert]

What worries me most is that my PH is steadily dropping now. With the kalk in the ato, it didn't drop so far. It's already down to 8.09 as i write this. I have my skimmer intake plumbed to outdoors, and decent surface agitation.

pH 8.09 is perfectly fine.

 

[Wet_Fretboards]

Expect to have to dose daily in most established reef tanks.

Even on top of the dosing pump? That doesn't seem right.

pH 8.09 is perfectly fine.

Went to 7.97 over the course of the night. Still sitting there...

 

[Randy Holmes-Farley Verified Community Expert]

Even on top of the dosing pump? That doesn't seem right.

Went to 7.97 over the course of the night. Still sitting there...

Oh, no. Just increase the dosing pump dose.

If you think you are causing too much precipitation, lower alkalinity and lower pH will help. There's nothing magic about higher alk except possibly faster hard coral growth.

 

[Wet_Fretboards]

Thanks