Any advantage for stable alkalinity or over stable pH overnight?

[edsbeaker]

Hi,
I don't have a refugium in my Red Sea reefer, so I don't have a light on during the night to keep pH up. When dosing alkalinity using a controller, is it more beneficial to dose around the clock so that alkalinity is more stable throughout the day even if pH falls at night OR dose alkalinity only at night, so that the pH is more stable around the clock but the alkalinity might drop a bit during the daytime? Does it matter?

 

[Martin Kuhn]

This is a bit depending on the recipee you use for dosing Alk, but anyhow ph value of your tank is affected only little as you dose only small amounts compared to your overall water volume.
Recipees using Na2CO3 or a combination of Na2CO3 + NaHCO3 drop the ph even less than using pure NaHCO3.

Especially if your tanks consume lots of Alkalinity a day (> 1 °dKH per day ) i would recommend to better keep Alk constant by dosing also over night.

For tanks that are generally "on the lower ph side" (do you have that issue ?) you should better check other measures like
- better ventilation of your room
- good movement of your water surface
- fresh air supply for your skimmer

best rgds
Martin

 

[Scorpius]

I use my refugium as a coral holding area that runs on an opposite light cycle as the display. Does it help? Dunno. lol

 

[saltyfilmfolks]

I dose a bit more of my alk for ph at night.
Around the clock has been shown to be benificial.

Yea, tough call.

 

[CodyRVA]

While the two are related, fluctuating ALK is far more detrimental to coral health than fluctuating PH, IMO.

Have you considered something like this:

 

[edsbeaker]

While the two are related, fluctuating ALK is far more detrimental to coral health than fluctuating PH, IMO.

Have you considered something like this:

Yes, I have and have done lots of research on them because I can't fit a refugium in the sump. But sadly, I didn't even connect that adding one wouldn't only help with the reduction of nitrate and phosphate, but also will help by allowing a reverse light cycle to keep pH up, and possibly the live algae, if I remember my biology correctly, could help increase the pH because it is absorbing CO2? I am using a CO2 scrubber right now to keep pH above 8. I think you are on to something! Thanks

 

[saltyfilmfolks]

Yes, I have and have done lots of research on them because I can't fit a refugium in the sump. But sadly, I didn't even connect that adding one wouldn't only help with the reduction of nitrate and phosphate, but also will help by allowing a reverse light cycle to keep pH up, and possibly the live algae, if I remember my biology correctly, could help rincrease the pH because it is absorbing CO2?

Yes. The coral anaons co2 and the refugium does.
But I would reccomend looking at the swing of both ph and alk to decide. Either could be insubstantial.

 

[edsbeaker]

Yes. The coral anaons co2 and the refugium does.
But I would reccomend looking at the swing of both ph and alk to decide. Either could be insubstantial.

I've calculated the change in my pH over 12 hours at night, and the change of the alkalinity over 12 hours during the day. My pH goes down from 8.08 to 7.98, but it looks like from the morning until night time, during those 12 hours my alkalinity would go from 9 to 7.5. It seems like that is more significant then the pH. Will the algae reactor help maintain pH similarly as a refugium?

 

[saltyfilmfolks]

IMO the ph is minimal.
That alk reading seems like an error.

 

[CodyRVA]

It really does depend on your system, how much ALK your system needs, but all I can say is there is no way I would even consider only dosing ALK over 12 hours vs 24. And yes a reactor of sorts will help. When my chaeto needs pruned my PH usually runs around 8.1. After pruning it drops to 7.7 until it regrows. The system shows no issues when I prune it, but testing reveals a definite drop. And I also run my lights on a reverse (overnight) schedule.

Keep in mind there are likely other options to resolve this...

 

[Randy Holmes-Farley Verified Community Expert]

Most of the alk demand may be during the day, so you can't really optimize both, but I'd dose 24/7 or just during the day.

 

[edsbeaker]

IMO the ph is minimal.
That alk reading seems like an error.

Could be a mistake, but I'm dosing 3.2 ml per dose X 12 = 38ml. According to the reef calculator if your all is at 7.5 and you want to increase it to 9 you need to add about 40 ml. But I dose 76 ml per day.

 

[edsbeaker]

Most of the alk demand may be during the day, so you can't really optimize both, but I'd dose 24/7 or just during the day.

Thanks Randy, that sounds good! Do you think it would be of help to get an algae reactor inline, since my pH is normally low anyway? Could it help with increasing pH By reducing some of the CO2?

 

[Salty1962]

I take my projected requirements and dose it 4X a day. So if I require 110ml of carbonate, I dose 27.5 ml 4x a day, reference only.

 

[Sabellafella]

Hi,
I don't have a refugium in my Red Sea reefer, so I don't have a light on during the night to keep pH up. When dosing alkalinity using a controller, is it more beneficial to dose around the clock so that alkalinity is more stable throughout the day even if pH falls at night OR dose alkalinity only at night, so that the pH is more stable around the clock but the alkalinity might drop a bit during the daytime? Does it matter?

You can try something like kalkwasser around nightime. Helped me a bit

 

[Flippers4pups]

I dose calcium hydroxide (kalkwasser) 24/7 via ATO, helps me keep alkalinity and PH more stable throughout the day and night.

 

[Keiffer the reefer]

My pH was ranging from 7.8-8.5 night to day. I converted my reefer 250 skimmer chamber to a fuge and started using an apex DOS to dose kalk for my top off water at night. My pH swing is now 8.1-8.4. Main part of my Alk dose is 24 hrs a day.

 

[edosan]

For ph, a co2 scrubber works great if co2 is the reason for low ph, basically is an air filter or co2 filter for the air intake of the skimmer, with soda lime.

 

[TravisParsley]

My opinion would be dose 24 /7, but do the majority of dosing at night. Say 20 percent during the day spaced out and 80 percent at night. Since you dont have a reverse light cycle set up in a fuge - I would think the PH swing would be more dramatic.

I would urge caution about alk levels going too high if using alk as a means to keep PH stable. Correct (not too high) and stable Alk levels are more critical than a PH swing, which are natural on reefs.

On another note, I noticed my PH during the day would not get much higher than 8.20 during the day with my Radion lights at 30 percent. Over a long adjustment period, I raised the intensity to 100%. This increased photosynthesis and my PH is now between 8.35 and 8.39 during the day.

My personal setup allows me to have a PH during the day around 8.39 and only drops to 8.21 at night by doing the following:

An airline to the skimmer from outside my home, macroalgae in a fuge on a reverse light cycle, dosing kalk 3 times a night for 1 minute each, dosing 98.8 ml of ALK during the night, and high surface agitation in the main display and a section in the refugium.

 

[edsbeaker]

My opinion would be dose 24 /7, but do the majority of dosing at night. Say 20 percent during the day spaced out and 80 percent at night. Since you dont have a reverse light cycle set up in a fuge - I would think the PH swing would be more dramatic.

I would urge caution about alk levels going too high if using alk as a means to keep PH stable. Correct (not too high) and stable Alk levels are more critical than a PH swing, which are natural on reefs.

On another note, I noticed my PH during the day would not get much higher than 8.20 during the day with my Radion lights at 30 percent. Over a long adjustment period, I raised the intensity to 100%. This increased photosynthesis and my PH is now between 8.35 and 8.39 during the day.

My personal setup allows me to have a PH during the day around 8.39 and only drops to 8.21 at night by doing the following:

An airline to the skimmer from outside my home, macroalgae in a fuge on a reverse light cycle, dosing kalk 3 times a night for 1 minute each, dosing 98.8 ml of ALK during the night, and high surface agitation in the main display and a section in the refugium.

Thank you! All great points. I also have radions that I have recently ramped up to 100% from 50% over the past month. Hopefully I will get the same results as you. My set up is newer, so corals are fairly new and haven't gotten to that growing stage yet, so like you bring up, that will probably help as well.
Either way, I think I will add a macro algae reactor. It will probably help in many ways, with no disadvantages.