Attn: Serious Chemistry Nerds...
- Thread starter bonebrake
- Start date
shoreliner11
Active Member
Ok, I know this its just going to take a little thinking...here it goes:
The reason why the light cycle effects pH is because of photosynthesis and respiration. During the night, there is a lot of higher levels CO2 which causes the pH to lower. An oversimplification is that more CO2 (carbonate ions specifically) the lower the pH from forming acids. As these levels rise and fall this causes your pH to rise and fall accordingly. Now there are lot of ways to limit this rise and fall by a higher alkalinity (buffering capacity) but this is the jist of it. Now this is very simple explanation so anyone feel free to go more in depth.
Aaron
The reason why the light cycle effects pH is because of photosynthesis and respiration. During the night, there is a lot of higher levels CO2 which causes the pH to lower. An oversimplification is that more CO2 (carbonate ions specifically) the lower the pH from forming acids. As these levels rise and fall this causes your pH to rise and fall accordingly. Now there are lot of ways to limit this rise and fall by a higher alkalinity (buffering capacity) but this is the jist of it. Now this is very simple explanation so anyone feel free to go more in depth.
Aaron
mudplayerx
Active Member
Shoreliner is right on the money...but just to make it more confusing because I'm feeling evil..... did you know that carbonic acid is a ph buffer, even though it is an acid and lowers the ph slightly? Muhaha.
bonebrake
Active Member
With photosynthesis occurring in the light, the carbon dioxide is pulled from the water keeping the pH stable and in darkness photosynthesis gradually decreases to a halt and carbon dioxide levels build back up reaching a maximum concentration before lights come back on. Without a good buffering capacity, the pH can sink drastically at night. I understand; thanks for the reply.
It is a buffer, but not a buffer to be desired in marine aquaria.
H2CO3 <---> CO2 + H2O
I think it buffers to +/- 1 pH unit within pH of 5.6. This is why stagnant RO/DI water will be a pH of 5.6 due to dissolved carbon dioxide in the water.
It is a buffer, but not a buffer to be desired in marine aquaria.
H2CO3 <---> CO2 + H2O
I think it buffers to +/- 1 pH unit within pH of 5.6. This is why stagnant RO/DI water will be a pH of 5.6 due to dissolved carbon dioxide in the water.
shoreliner11
Active Member
And here I thought you needed a simplified explanation. Seems like you just needed a nudge in the right direction.
Aaron
Aaron
danedodger
Member
Yep, I agree... GEEKS!!!
Smart guys are just HOT HOT HOT though!!!! Cute but dumb you can have great ummm "relations" with (keepin it at least PG here
) but it gets real old real fast having to tell them which foot to put their shoes on day in and day out!! Why settle for that when you can have THAT and interesting, thought provoking, mind stretching conversations with too??? Or am I the only "geek worshipper" round here?
Any of you guys single?
Smart guys are just HOT HOT HOT though!!!! Cute but dumb you can have great ummm "relations" with (keepin it at least PG here
fireemt_us
Member
Last I checked this wasnt a dating service. And what with all of that said would you make of a Smart guy who is good looking and good at "relations" ???
danedodger
Member
For your first "sentence", it was a JOKE! Lighten up!
The second part I'll need someone to correct your grammar before I even understand what you said.
The second part I'll need someone to correct your grammar before I even understand what you said.
darth tang
Active Member
Just to help out.
Translation:
And what (with all of that said) would you make of a Smart guy, who is good looking, and good at "relations" ???
Basically implying fireemt is everything you are looking for. If you two make a connection my hook up fee is one Lionfish of any random species.
Translation:
And what (with all of that said) would you make of a Smart guy, who is good looking, and good at "relations" ???
Basically implying fireemt is everything you are looking for. If you two make a connection my hook up fee is one Lionfish of any random species.
danedodger
Member
Basically implying fireemt is everything you are looking for. If you two make a connection my hook up fee is one Lionfish of any random species.
I guess I'll have to pass, in that case, but thanks for the translation! I can't afford any lionfish right now though! :hilarious
I guess I'll have to pass, in that case, but thanks for the translation! I can't afford any lionfish right now though! :hilarious
J
jdragunas
Guest
ok good, now that all of you nerds are in one spot, i have a few questions that i'd like clearing up. I understand that having the light on the fuge on at night will help stablize your PH, but why do you need to do this? Doesn't the sun go down at night over the ocean? So doesn't the PH drop at night in the ocean? So doesn't stablizing the PH at night by having reverse lighting schedules actually NOT imitate the real environment?
And secondly, i've heard that your PH is affected by the cycle. I've said that's not true, and asked why PH would be affected by cycling, but never got a response. So is it or is it not affected by the cycle, and if it is, why?
And secondly, i've heard that your PH is affected by the cycle. I've said that's not true, and asked why PH would be affected by cycling, but never got a response. So is it or is it not affected by the cycle, and if it is, why?
darth tang
Active Member
The Ocean is a larger body of water compared to our tanks...therefore it it is easier for Our tanks to react as they do over night than the Ocean. It is a size thing as well as a current thing. The Ocean is always light some where, and currents will move water from those light areas to dark areas. You will notice the smaller the tank the more noticable the PH change is. There is a slight difference between my 55 and smaller tanks compared to my 140 gallon tank at night.
The cycle normally will affect your PH. But the susequent water change afterwards corrects it. It also depends on how hard you tank cycles on how much the PH will be affected.
The cycle normally will affect your PH. But the susequent water change afterwards corrects it. It also depends on how hard you tank cycles on how much the PH will be affected.
ophiura
Active Member
Dang. He beat me to it!!! Argh!
As far as cycling, well, it is a period of intense microbial activity and decomposition...and even aerobic microbes give off CO2. So when you have lots of activity, you have an increase in CO2 production, and a decrease in pH. Might also be compounded by lack of circulation or instability in calcium/alkalinity/etc which might be characteristic of a young tank/inexperienced hobbyist.
As far as cycling, well, it is a period of intense microbial activity and decomposition...and even aerobic microbes give off CO2. So when you have lots of activity, you have an increase in CO2 production, and a decrease in pH. Might also be compounded by lack of circulation or instability in calcium/alkalinity/etc which might be characteristic of a young tank/inexperienced hobbyist.
danedodger
Member
Larger body of water means more stability and sunup in some other part of the world may act in somewhat the same capacity as leaving lights on at night in your fuge. Gotcha!!
But how and why does the cycle affect the pH? I too really want to better understand the chemical composition of our aquariums and how each level affects the others.
But how and why does the cycle affect the pH? I too really want to better understand the chemical composition of our aquariums and how each level affects the others.
danedodger
Member
Ahhh ok, so more CO2 = lower pH! Hmm so assuming that the rising ammonia and such didn't kill them, when you're cycling your tank the pH might more reliably stay higher if you added plants to take in the CO2?
darth tang
Active Member
I would think so in theory. I have never tried it.....chaeto algae and such may help however.
ophiura
Active Member
In general, I would just stay on top of the chemistry of the system in terms of alk, gas exchange, etc. The pH drop should not be so significant as to be a real issue...if it is, there are probably more significant issues going on.
Another factor in running a refugium light 24/7 might really be that you have a system PACKED full of algae that does actually respire, adding more CO2 than a tank without a refugium. Repiration of course would be the dominant process if the lights are off...so if you had a cycling tank, without a refugium, and turned the lights off...you might still have a problem. But critically significant pH fluctuations would only occur, IMO, if your alkalinity is too low.
Another factor in running a refugium light 24/7 might really be that you have a system PACKED full of algae that does actually respire, adding more CO2 than a tank without a refugium. Repiration of course would be the dominant process if the lights are off...so if you had a cycling tank, without a refugium, and turned the lights off...you might still have a problem. But critically significant pH fluctuations would only occur, IMO, if your alkalinity is too low.