Aeration having similar effect of reverse photo period

[davidryder]

I was wondering if anyone might agree that providing increased aeration after the lights go off for the night will have the same effect as turning the lights on in your refugium/sump when the lights go out for the night.

I was wondering this because I have a HOT magnum in my refugium that I run ONLY at night because of how many bubbles it produces (it breaks the surface of the water). I also thought that more flow at the surface would mean more gas exchange. This would in turn raise the pH?

The same thing is achieved when we turn our refugium lights on when we turn the tank lights off at night. I'm not sure if it would have the same magnitude but I would be curious to know.

 

[Outerbank]

I like your thinking, but I think the effects you mentioned would not be as great as a photoperiod. Ideally, you would use the above in combination with light.

 

[silverwolf72]

It does to some degree, prob is most homes have a higher than normal CO2 so at the most it will balance to that lvl. Reverse cycle has the benefit of the uptake of CO2 and the release of O over just balancing to what ever lvls are in the room.

 

[davidryder]

I'm going to conduct a 15 day experiment I'll post the results here.

 

[mandm25254]

as long as your house doesn't have a high co2 level assuming you are drawing air from your house.

 

[MCsaxmaster]

As mentioned, aeration will reduce the dissolved CO2 in the tank water if you are aerating with air that has a lower pCO2 than the tank water. Since most folks have elevated CO2 in their homes, this doesn't necessarily do much for some folks. Heavy aeration with outdoor air can usually help though.

cj

 

[DrBegalke]

this sounds like a great study, you might be interested in the video on oxygenation at reefvideos.com

 

[m2434]

There was an intresting thread on this a few years ago. Unfortunatley I have not been able to find it again... If I remember correclty some skimmerless tanks had extreamly low PH at night (i.e low 7's to upper 6's), but just having a skimmer (i.e. running all the time) was enough to buffer the PH substantially. I don't think anyone tried just running the skimmer at night. I would love to see an experiment, you also might try just having the skimmer on all the time and see if there is any difference to the reverse photoperiod.

 

[DrBegalke]

Here's my guess, it will cause a very minor bump in oxygenation/pH, but nothing like a refugium/photosynthesis would.

 

[MCsaxmaster]

Yeah, the effect is going to depend strongly on how much aeration there is and what the partial pressure of CO2 (pCO2) is in the air. Air with a very low pCO2 with very little aeration is useless and strong aeration with air that has a high pCO2 is useless.

Also, a pH dropping to the upper or even middle 7's I can believe, but one dropping down to the upper 6's...well, that's a calcium reactor It would take a very screwed up tank to be able to do that.

cj

 

[davidryder]

I will put together a graph at the end of this. The first five days all lights will remain off at night and all lights will remain on during the day. No aeration will occur during this time.

I'll measure the pH before the lights come on and before they go out for the evening.

My pH was 7.8 @ 82.6* this morning right before the lights came on (refugium lights were off).

The main purpose of this is to

1) Observe the magnitude of pH change during non-photo periods

2) Observe the magnitude of pH buffering in regards to reverse photo period lighting schedules.

3) Observe the magnitude of pH buffering in regards to aeration similar to that produced by a skimmer.

Any other thoughts? I can't measure the pCO2 unfortunately.

 

[MCsaxmaster]

I would use one of the 4 treatments: 1. no lights, no aeration, 2. lights + aeration, 3. lights, no aeration, 4. no lights, aeration. I'd then randomly assign days so that you have at least 3 replicates of each of these--that'd give you 12 experimental days. Then, measure pH just before lights on in the morning and just before lights out at night. The stats will be easy to put together and compare. In just under 2 weeks you should have a good idea of which is or is not very effective for you in the current situation (if the room air changes, the effect will change, hence replication is necessary).

cj

 

[m2434]

<a href=showthread.php?s=&postid=10878663#post10878663 target=_blank>Originally posted</a> by MCsaxmaster
dropping down to the upper 6's...well, that's a calcium reactor It would take a very screwed up tank to be able to do that.

cj

Thank you - my point exactly! Fish release CO2 and when there is no light so does algae. Get a tank with heavy algae growth, add in some crushed coral sand and wala you essentially have yourself a calcium reactor!

 

[MCsaxmaster]

...which would be a very, very bad thing, if one wants to have healthy/living organisms...

 

[m2434]

<a href=showthread.php?s=&postid=10882359#post10882359 target=_blank>Originally posted</a> by MCsaxmaster
...which would be a very, very bad thing, if one wants to have healthy/living organisms...

Very true.

Although interestingly I found this article, researchers actually grew Proites at PH7.2 for 7 weeks. It grew at half the rate compared to PH8, but it grew!

Porites experiment

Sorry, getting off topic ....

:eek2:

 

[MCsaxmaster]

Yes, but for other corals people have measured dissolution in the dark at a pH < ~8.0 (Schneider and Erez, 2006). I wouldn't push things

 

[m2434]

<a href=showthread.php?s=&postid=10882921#post10882921 target=_blank>Originally posted</a> by MCsaxmaster
Yes, but for other corals people have measured dissolution in the dark at a pH < ~8.0 (Schneider and Erez, 2006). I wouldn't push things

Never said you should. Just like odd facts (and I'm in kind of a wierd mood taday...)

 

[m2434]

<a href=showthread.php?s=&postid=10878940#post10878940 target=_blank>Originally posted</a> by MCsaxmaster
I would use one of the 4 treatments: 1. no lights, no aeration, 2. lights + aeration, 3. lights, no aeration, 4. no lights, aeration. I'd then randomly assign days so that you have at least 3 replicates of each of these--that'd give you 12 experimental days. Then, measure pH just before lights on in the morning and just before lights out at night. The stats will be easy to put together and compare. In just under 2 weeks you should have a good idea of which is or is not very effective for you in the current situation (if the room air changes, the effect will change, hence replication is necessary).

cj

Intresting, but what are you going to do about the inherent autoregression?

 

[m2434]

or if you meant to alternate days, you still need some kind of washout period..

 

[davidryder]

Results of first 5 days

Results of first 5 days

Ok, here are the results of the first five days:

Again, this was measured right before the lights came on in the morning and right before the lights went out at night. Refugium lights were off at night, on during the day.

I expected a larger pH swing than this... any thoughts?

The next five days the refugium lights will stay on during the night and go off during the day.