Will Microalgae Reactor help with pH swings at night.

[rob safron]

Per the title, I am having a hard time with pH. Prefer not to setup a full refugium in my sump and wondering if a algae reactor will help keep pH up at night. Currently pH during the day hits about 8.1 and drops to 7.1 overnight. Anyone with experience using a reactor? Nutrient control is not my issue or goal, mainly pH. Tried windows, can’t keep open all the time.

 

[Randy Holmes-Farley Verified Community Expert]

pH 7.1 cannot be real. Is that a typo? How are you measuring pH?

A macroalgae reactor will help bring up pH when lit.

 

[rob safron]

Not a typo. I run 2 pH probes on my Apex. They both run the same. Just re-calibrated last week.

 

[rob safron]

 

[Johnson556]

Yeah, I calibrated my probe last Sunday and it was reading a min of 6.4 and a max of 10.7, by no means reality. After a day it was back to reading normally (8-8.15) but I'll still be replacing it.

How long has it been since calibration?

Also, I was suffering from low PH during a heat wave this summer and ran an airline from my skimmer to outside. Best thing I've done to my tank yet. Brought my PH up .2

 

[rob safron]

I did it twice the last week. You can see on the graph the last cal was on Aug 11. One probe is less than a year old. The other is not much older. I do notice sometimes after cal they read low and come back up but it’s been this low most of the summer.

 

[reeferfoxx]

Looks like 7.7 not 7.1?

 

[rob safron]

 

[reeferfoxx]

Currently pH during the day hits about 8.1 and drops to 7.1 overnight.

pH 7.1 cannot be real. Is that a typo?

Not a typo.

Ok. Clearly a typo. Although your lowest ph drop won't kill anything, your swing is quite high and could improve.

To answer your questions, yes a macro algae refugium or reactor will improve pH at night but only as long as nutrients are available. Summer time we keep the windows closed and therefore co2 increases. The pH dip is a result of high co2.

 

[Randy Holmes-Farley Verified Community Expert]

Not a typo. I run 2 pH probes on my Apex. They both run the same. Just re-calibrated last week.

But it is, almost without question, not accurate at pH 7.1. Must be electrical interference or some other issue. Many people have issues with controllers and pH measurement.

Any calcium carbonate in the tank would be dissolving at that pH. Like your whole tank being a CaCO3/CO2 reactor.

 

[Randy Holmes-Farley Verified Community Expert]

Looks like 7.7 not 7.1?

Right. I see 7.7 on the graphs too. That is reasonable, but certainly on the low end.

 

[rob safron]

So your are assuring me that 2 apex probes, 1 in the sump and 1 in the display tank that concur with each other are incorrect. Even though they both have calibrated OK and display the cal solution pH correctly. What sort of test is there to see if it’s electrical interference. Also, the graphs by look like 7.7 but the actual numbers show 6.9 and 7.1 this morning.

 

[rob safron]

Ok. Clearly a typo. Although your lowest ph drop won't kill anything, your swing is quite high and could improve.

To answer your questions, yes a macro algae refugium or reactor will improve pH at night but only as long as nutrients are available. Summer time we keep the windows closed and therefore co2 increases. The pH dip is a result of high co2.

My concern for sure. I do run low nutrients, nitrate just under 1 and phosphates at 0.01 but feed very heavy and dose Aquaforest ABEV. I do have small amount of algae growing on the glass and rock so I know there is usable nutrients in the water.

 

[Randy Holmes-Farley Verified Community Expert]

So your are assuring me that 2 apex probes, 1 in the sump and 1 in the display tank that concur with each other are incorrect. Even though they both have calibrated OK and display the cal solution pH correctly. What sort of test is there to see if it’s electrical interference. Also, the graphs by look like 7.7 but the actual numbers show 6.9 and 7.1 this morning.

Yes, I'm assuring you that pH 7.1 is not accurate. Maybe the display is messed up because the graph is normal. Maybe two different APEX probes are interfering with each other.

Take out a cup of tank water and measure pH in the cup. Just before or after, measure the pH of a pH 10 buffer (or 8 or 9, not 7) to check it.

Also, try this test:

pH And The Reef Aquarium
http://www.reefedition.com/ph-and-the-reef-aquarium/

The Aeration Test

Some of the possible causes of low pH listed above require an effort to diagnose. Problems 3 and 4 are quite common, and here is a way to distinguish them. Remove a cup of tank water and measure its pH. Then aerate it for an hour with an airstone using outside air. Its pH should rise if it is unusually low for the measured alkalinity (Figure 2). Then repeat the same experiment on a new cup of water using inside air. If its pH also rises, then the aquarium’s pH will rise simply with more aeration because it is only the aquarium that contains excess carbon dioxide. If the pH does not rise in the cup (or rises very little) when aerating with indoor air, then that air likely contains excess CO2, and more aeration with that same air will not solve the low pH problem (although aeration with fresher air should). Be careful implementing this test if the outside aeration test results in a large temperature change (more than 5°C or 10°F), because such changes alone impact pH measurements.

 

[reeferfoxx]

Also, the graphs by look like 7.7 but the actual numbers show 6.9 and 7.1 this morning.

Besides the pH probes what is the actual test you are using to say it's dropping to 7.1? Your graphs show no such number.

A voltimeter can test to see if electricity is in the water.

 

[rob safron]

The Apex displays the pH number. See pic above.

 

[reeferfoxx]

#reefsquad Does the graph show 7.7 or 7.1? Is it Laurel or Yanni? Is the dress black or gold?;Facepalm

 

[rob safron]

So I pulled a cup of tank water out to test on. Shows 7.0 and the 10.0 solution warmed for a couple minutes shows 9.95. Guess I’ll try purchasing a new probes to see if that corrects things

 

[rob safron]

Maybe it’s the whole apex system since 2 different probes are doing this crazy thing.

 

[reeferfoxx]

@rob safron It's difficult to say. The graphs and screenshots you show us look normal. The left side of the graph is the available range of measurements. You have a graph range set between 7 and 10, at the bottom. All these things look normal. The Apex even says your average is 7.8. If you have a drastic drop in pH, your average shouldn't be 7.8 but lower in the 7.5 area.