Do Corals Consume Alkalinity When the Lights Are Off?

[BigJohnny]

Hello everyone,

I was thinking about doing my calcium and alkalinity testing at night and dosing as needed but I wanted to dose my alkalinity in the morning. Would the alkalinity value change from when I turn the lights off to when they come on in the morning and is this a significant change that my dosage should be adjusted?

Thank you and happy reefing!!

Yes and also precipitation occurs, however my tank consumes 75% of daily alkalinity during the photoperiod with 50% during the 5 hour peak. This is due to higher pH and increased photosynthesis.

 

[Hans-Werner]

Corals also calcify at night. There are calcifying mechanisms that are independent of light. Without light coral calcification is reduced but not stopped.

 

[jda]

Also keep in mind that snails, clams and coralline are all major carbonate consumers. Frags are an afterthought in a tank with lots of purple.

 

[erky]

cool thread, I will have my alk monitor set up in the next day, and I will be happy to show the results of my tank.

My thinking was that alk would be consumed in the photo period, and I actually cut out later in the evening dosing times, maybe that is why my tank had some issues. If everyone is seeing an influx in 21:00-24:00 consumption looks like I made my alk less stable by having a swing when the doser started at 1am.... this hobby has so many mysteries and still is so fun!

 

[jda]

Most animals do not grow when they are consuming and storing energy. They grow when they are at rest. Most is not all, for sure. This is a long way from calcification in the ocean, and the very definition of a false equivalency, but mammal bones do most of their growing at night.

 

[MrTaleb]

I have heard that corals in the ocean extract there long tentacles to capture critters that are floating buy. during the day they collect photosynthesis. After taking multiple tests with red sea for DKH i have seen in my results that its lower come morning once the lights just turn on then at night when they turn off. so i dose more during the night time then during the day when the lights are on.

By*

 

[Deep]

I run an alkatronic that measures every 4 hours and have quite a few frags and mini colonies. My Alk consumption increases after my halides go off at 6 pm and most of the consumption happens from 6 pm to midnight.

 

[TX_Punisher]

According to my trident my cal often drops from midnight to 6am as my ca reactor turns off at 1030p. I dose a few ml of cal additive
to keep it stable.

my alkalinity often rises between those hours and has for over a year. No dosing of any alk additive happens after 1030 and before 0730.

 

[Michael Rancour]

Now that alkalinity monitors are available we are starting to get insight into daily demand. After a few weeks of hourly testing, I was able to see that my tank uses most of its alkalinity from a few hours before lights out until a few hours after lights out. There is zero consumption from about midnight to 7am. I believe others have noticed that most of their consumption is towards the end of the photo period as well.

The exact same thing happens to me. I’ve also tested and the highest demand in alk is from 6 pm to 00:00. Whereas from 00:00 to 6 in the morning there is 0 consumption.

 

[burton14e7]

Bringing this thread back to life because it was in my google search results for "when is alkalinity used the most". Just recently I noticed my alk being perfect during the day and then dropping way more than normal at the midnight reading. My tank is finally getting back into gear after the 36 hour power outage Texas experienced this winter that wiped out my tank. The morning through the 6 PM reading have been spot on so I added in a new dosing regimen from 6 pm - midnight to increase dosing during that period. I'm glad I found this post to corroborate what I've been seeing and adjusting for.

 

[Heabel7]

Resurrection . Any more folks willling to share what their alk consumption is like at different times of day? So many have auto testing now. It would be nice to here some more evidence of when our corals and other organisms are consuming it.

looks like the last few are saying 6pm-midnight is peak. What’s your photoperiod? That would probably have a major role in the timeframe.

 

[trietnguyen000]

I manually test my 24gal tank religiously. I have found that my alk consumption are mostly during day time. There is very little to no alk consumption from 1800 - 0600 for me. I’m a newbie and still learning. Could be multiple variables (lighting, flow, parameters, type of organisms, etc) that affect alk consumption at a certain time and no specific standard?

 

[drawman]

So it tracks kinda like pH, but maybe a little behind it? Interesting.

Makes you wonder what would happen in tanks where pH is stable