"Plant Life" experiment results

[bang guy]

Hi all,
Most of us are aware of controversy around our very own Beaslbob AKA, Mr. Plant Life. Some of us get exasperated and I've even seen anger toward the relentless assault on our current standard reef keeping practices.
First, I'd like everyone to step back and remember that this hobby is still not an exact science and there are many ways to keep reef tanks successfully. Conversely, the generally accepted practices don't always work either. There are just too many variables to make one method fit all situations.
I hope we all can understand that as exasperating as it can be, controversy IS A LEARNING OPPORTUNITY. This is the stuff that makes us THINK. This is a GOOD thing. Conversely, if you are stating a controversial opinion, please clearly indicate that it may not be the accepted practice for the hobby.
All right, 'nuff of my opinions I hope.
_________________________________________________
Purpose -
To determine if adding Caulerpa racemosa to a display tank will stabilize PH levels.
Background -
I keep hearing that adding Caulerpa to a display tank will consume excess Carbon dioxide and stabilize PH. I've yet to see any proof (numbers). So, I decided to get the numbers myself.
Setup -
Three 10 gallon glass tanks set up as consistently as possible
1/2" sand bed for filtration
airstones for water movement
All three tanks are partially submerged into my Lagoon to keep the temp stable at 78F. I tried heaters but I was not able to keep all three tanks the same temperature.
Lighting is provided by three 4' VHO bulbs lit using an IceCap 660 ballast. The bulbs are used URI Aquasuns but they're still pretty bright. The bulbs span all three tanks so all tanks are being lit by identical bulbs.
Bioload is provided by a pair of Silver Mollies of similar size in each tank.
Initially, the tanks were plumbed to my reef system. This provided a quick cycle time but more importantly it made all three tanks nearly identical as far as water conditions. They were disconnected one week before I started taking PH readings.
Lighting times are 8pm - 8am set by a timer. The Lagoon lighting used the same timer. The basement where the experiment took place is pitch black when the lights are off except when I have my flashlight on
PH was tested using a newly purchased Red Sea Alkalinity/PH test kit.
No water changes or topoff was performed during the experiment.
A handful of Caulerpa Serrulata was added 01/07/04 at 7:00 am to tank 1.
A handful of Caulerpa Racemosa Peltata was added 01/07/04 at 7:00 am to tank 3.
Tank 2 was used as a control tank and only has coralline and diatoms, similar to tanks 1 and 3 without the Caulerpa.
Conclusion –
I probably added too much Caulerpa for a 10-gallon tank. The results show an indication for PH to have a wider range with an excess of algae (tanks 1 & 3) vs. a moderate amount (tank 2). I am not indicating that this is a bad thing, just that it is contrary to the belief that algae in a display tank will stabilize PH.

 

[joemack]

I hear that macros with light 24/7 (like in your fuge) will help stabilize your PH because photosynthesis goes around the clock and your macros wont stop producing oxygen and taking in CO2. When the lights go out on the fuge the macros can take in oxygen and put out CO2.
That from what I hear but I just learned about Alk/Calcium 2 days ago so im a guru or anything. Not trying to start a fight or anything... Just taking advantage of this great learning opoortunity

 

[beaslbob]

bang: I appreciate you efforts here but where is the no plant life tank?. Your results are that corraline and diatoms tank has less ph variation.
My concern is all the people posting that after they get rid of say hair algae with cleaner crews they start losing fish. Further that the ph drop is a symptom of excess carbon dioxide. And that the excess carbon dioxide is what is weaking and killing the fish. So perhaps ph variance just as in the ocean is not all that important.
Again I really do appreciate your efforts here and the results are interesting. They just have no bearing on whether a newbie should add plant life to a new system.

 

[shoreliner11]

Well I have a follow up question for you bang. Despite the fact that there is a night time and day time for the lights, would it be best to run my makeshift fuge(half of cpr bakpak with spaghetti macro) lighting at night and alternate it from the normal tank lighting? Would this help stabilize my pH? There is a small amount of halimeda I believe its called in my tank at the moment and I was wondering if the alternating lights would help? Hope I made myself clear...if not, well, oh well. Thanks.

 

[shoreliner11]

beaslbob, I was under the impression that the pH of the ocean is amazingly stable...as a whole. I understand that at night time there is no photosynthesis taking place but the amount of gas exchange taking place between the ocean and air is enough to counteract this. I understand this is different depending on the exact habitat and water depth, but isn't the most stable pH what we are trying to simulate...ie the ocean? I am actually looking for clarification on this subject. Thanks for the help.

 

[beaslbob]

Originally posted by Shoreliner11
beaslbob, I was under the impression that the pH of the ocean is amazingly stable...as a whole. I understand that at night time there is no photosynthesis taking place but the amount of gas exchange taking place between the ocean and air is enough to counteract this. I understand this is different depending on the exact habitat and water depth, but isn't the most stable pH what we are trying to simulate...ie the ocean? I am actually looking for clarification on this subject. Thanks for the help.
I though so too but bang (i think) reported that ph does drop at night from daytime 8.4 or so to around 7.7 or so in the ocean. Due to plant action.
I never checked ph until my original setup with too much bioload too fast started losing fish even though nitrItes were 0.0. The fish developed white spots, deteriorated, started breathing heavy, and slowly died. Then I discovered the ph (daytime) had dropped to 7.4. The same water in a new tank had a ph of 8.4 when I added my first macros. The display ph rose to 8.4(daytime) and stayed there with the macros added. And the fish stopped dieing and my tang recovered from white spotes and has lived for 8 months now.
My concern is people entering this hobby are experiencing the same thing I did.

 

[nicky1.8t]

thanx for the good info. but do you think there might be different results if you didnt plumb into the lagoon, i belive it may be to stable of a system for an experement like this.

 

[joemack]

true that

 

[bang guy]

Originally posted by JoeMack
I hear that macros with light 24/7 (like in your fuge) will help stabilize your PH because photosynthesis goes around the clock and your macros wont stop producing oxygen and taking in CO2. When the lights go out on the fuge the macros can take in oxygen and put out CO2.

This experiment was strictly about display tanks and Caulerpas affect on PH. Since lighting a display tank 24/7 is not an option if would be meaningless to thest it. I agree that it would probably stabilize PH.

 

[shoreliner11]

How rude of me...thanks a bunch

 

[karajay]

Originally posted by Kip4130
outside of any conclusions ... i would just like to say thanks to bang... and people like bang.. that take the time to conduct experiements.
Yeah...what he said!

 

[007]

Originally posted by nicky1.8t
thanx for the good info. but do you think there might be different results if you didnt plumb into the lagoon, i belive it may be to stable of a system for an experement like this.
It wasnt plumbed into the lagoon, but merely resting in there as a heating constant.

 

[007]

A couple questions here . . . does coralline respirate? What about diatoms . . . if so, then bob has a valid point. However in response, the items in question were macroalgaes, and as far as I am aware, coralline and diatoms are both forms of microalgaes (diatoms are neither I think though).
Also, it has been my understanding that in all actuality the ocean undergoes rather regular pH swings, especially in the vincinity of many reefs. Sometimes rather massive ones at that. Granted the pH obvioulsy stays within a certain range, but variances do occur.
Do you by chance have any more numbers bang? I can run some statistical analyses in SPSS if you do . . .

 

[beaslbob]

i agree. the lagoon was just used to stabilise the temperatures not for the actual water in the tanks.
And in case I can across too negative, Thanks to bang. These experiments do take time and show a thoughtful controlled appraoch. Bang If you did not get that from my original post, please accept my apologies. Back seat driving can be a real distraction.

 

[bang guy]

Originally posted by beaslbob
bang: I appreciate you efforts here but where is the no plant life tank?. Your results are that corraline and diatoms tank has less ph variation.
That's a very interesting point. Perhaps I should repeat and setup tank 3 as void of all algae or as much as possible.
All 3 tanks had similar amounts of coralline & diatoms at the start. I can see arguement of what you're saying and I believe it's valid. OTOH it show that the types of Caulerpa I used increase PH fluctuation for the other two tanks.
Originally posted by beaslbob
Further that the ph drop is a symptom of excess carbon dioxide.
I agree 100%. It is my assumption that excess Carbon dioxide was produced by the Caulerpa and dropped the PH values significantly in the dark. I would guess that had I added two handfuls of Caulerpa the PH could have dropped even further, perhaps even into the CO2 toxicity range.
Again.. another potential experiment.
Originally posted by beaslbob
They just have no bearing on whether a newbie should add plant life to a new system.
I agree. But it does seem to indicate that one should not add Caulerpa to a display tank and expect the PH to stabilize.

 

[007]

Are you implying that caulerpa produces CO2 in the dark?

 

[beaslbob]

Originally posted by 007
A couple questions here . . . does coralline respirate? What about diatoms . . . if so, then bob has a valid point. However in response, the items in question were macroalgaes, and as far as I am aware, coralline and diatoms are both forms of microalgaes (diatoms are neither I think though).
....

Absolutely!!!! Corraline and micros do respirate. I just purchased a micro algae culture kit and the reference book detailed the actions of the algaes. I could not tell the difference between that micro actions and what i have read on macro/plant or even the green coral actions.

 

[rick58]

Nice work, it's good to see some hard numbers. It appears, on the surface, that plant life will not stabalize your pH unless it is used too offset an increase in pH from some other source during the photoperiod. Is this correct?

 

[007]

I know that micro's such as hair algae respirate, but do coralline and diatoms (which like I said, I am not so sure are even an algae)

 

[bang guy]

Originally posted by Shoreliner11
would it be best to run my makeshift fuge(half of cpr bakpak with spaghetti macro) lighting at night and alternate it from the normal tank lighting? Would this help stabilize my pH?
I have done this in the past and it does work. On my current system the Lagoon is lit opposite my display tank. The PH is fairly stable.