Someone wanna miss prove this...

jonnywater

Member
I hear on most boards that SG should be kept around 1.025 for reef tanks. On the reefs, it ranges from 1.020 to 1.030. Now to my information - according to 30 something marine biology books - CO2 is at its highest levels with lower levels of SG. This in turn causes hard corals and some soft corals that use "zoo" to survive, to produce for aragonite and develope faster growth. Hense they are taking in more oxygen. The lower the gravity it also produce more "air" for the everything else in the tank also
The fact that the common temp on most reefs is between 70 and 85 degrees. Now most animals use temp as a basis (along with the lunar cycle) to find out good spawning times. So my question is, why do most people that have reef systems talk about needing a higher SG? or a temp that is around 78. Because with a consistent temp of around 75 and a SG of 1.022 or so, it is supposed to help control PH fluxes and the precipitation of calcium.
I just dont get it.
 

speg

Active Member
Well.. keep a reef tank at 1.022 and document how everything is doing.. then down the road slowly raise it to 1.025/26 and again document how things are... and decide for YOURSELF the best salinity for your livestock.
I personally have two reef tanks. Both are at 1.025 salinity but the temperatures are different. One is at 82/83 and one is 77/78. Both keep different things better than the other.. but I cant say for sure that its because of the slight difference in temperature.
 

jonnywater

Member
WHY would I do that? I can slowly drop it now because I have a high altitude system and can take it to 1.022 without it causing a major problem. Even that shows that its true. Since there is less CO2 at higher altitude, I guess reef tanks are supposed to be kept at a max of 1.024. Bottom line is that more CO2 is going to present and tolerable by the corals at a lower SG. Which in turn will cause the corals to grow faster and stabalize many of the chemicals in a tank.
 

chadman

Active Member
with the lights on my 30g my tanks temperature will rise 3 or 4 degrees over the course of the day....is this a bad thing?
 

speg

Active Member
Originally Posted by chadman
with the lights on my 30g my tanks temperature will rise 3 or 4 degrees over the course of the day....is this a bad thing?
You'll probably not see any negative effects with a 3-4 change. If you could keep it the same temperature all the time that would be great though.. but you're always gonna have a little change!
 

chadman

Active Member
you'd think when then sun is out over the reef that the temp would go up slightly....but i guess the ocean is a slightly larger body of water than my tank
 

ophiura

Active Member
I think it is an oversimplification. It is not just about CO2, otherwise we would all just pump our tanks full of CO2 like with planted tanks.
There are A LOT of factors that go into calcification. I suggest googling several articles on calcium and calcification by Randy Holmes Farley.
In addition in most areas of the reef the salinity is 35 to 36ppt. At the specific gravity of 1.020, what was the temperature?
The important thing is to keep animals as best you can under the conditions from which they were most likely collected. For most indo pacific animals this correlates to a temperature from 78-84 degrees, a salinity of 35-36ppt (or roughly a specific gravity of 1.025-1.026)
Ron Shimek has a very good article on natural reef salinities and temperatures. Randy Holmes Farley also has a article on specific gravity.
From Shimek's article...
Many reef animals, such as corals, sea anemones, sea stars and some worms, are osmoconformers and have very limited capabilities for internal regulation of salinity or other ions. Even though they do not have much capability to alter their internal osmolarity away from that of the surrounding medium, such osmoconforming animals will spend up to 80 percent of their metabolic energy maintaining internal cellular ionic balances. This relatively large amount of energy being spent to shuffle ions back and forth across cell boundaries means that these animals simply do not have much latitude to adjust to variations of salinity in the water surrounding them.
The animals may very well be severely stressed at lower specific gravities, regardless of whether conditions would be good for calcification.
What is published in marine biology books actually has limited impact, IMO, on reef tanks.
I will assure you, however, that lower specific gravities are a severe stress on several invertebrates we try to keep...and often fatal.
 

jonnywater

Member
I would like to get a # from you Ophiura of any place you can get ahold of that collects specimens at around 80-84 degrees outside of about 3 weeks out of the year. It takes nearly a month for the ocean to raise one simple degree and there are.........well..........12 months in a year.
I suggest you do a google search for "wholesale fish collectors" and ask them what SG and temp they collect their specimens at. I will keep this post open until then. And there isnt an entire chemical or organism on this entire planet that is all about a ONE item. However that is why CO2 reactors are so expensive and used so highly by marine aquariasts. It takes a HUGE deal out of the guess work for making sure your PH is stable. Which in turn corrects your alkalinity and maintains calcium levels. So yes, CO2 IS AND ALWAYS WILL BE a HUMUNGOUS part of the balance of a tank. See how that works? with a lower SG you have less pressure hense more CO2 in your system. 1 + 1 = 2
As much as I would love to "google search" something myself. I think the 35 or so marine biology books should cut it. Especially since 70% of them were written by people that had actual doctorates.
LOL. Still funny. Seriously - try to find a single collector that pulls anything out of water that is 1.026 and near 84 degree water at any time except for maybe the end of august. One contradicts the other.
 

jonnywater

Member
"What is published in marine biology books actually has limited impact, IMO, on reef tanks."
That makes a lot of sense. Because why would a book about the actual chemistry of the ocean have anything to do with someone trying to recreate that exact atmosphere. HAHA
That's like me saying that a carpet anemone will sting me in the wild but not in my tank.
"I will assure you, however, that lower specific gravities are a severe stress on several invertebrates we try to keep...and often fatal."

Yeah, I can understand that. If I dropped my SG to 1.012 then I would probably have some problems. Anyone raise their hand, please anyone at all, that has EVER IN THEIR LIFE heard about any marine organism that would die or even have problems if your dropped your SG from 1.025 to 1.022. ANYONE??? Outside of an adjustment period. Just like with a HIGH SG of 1.033 you can burn corals. But no one here is even talking about changing it that drastically.
 

celacanthr

Active Member
Look, there is no need to attack anyone.
If people have had overwhelming success by keeping there tanks at 1.027 and at 82 degrees, and you believe that they aren't doing it properly, then settup a tank with a specific gravity of 1.02, and a temperature of 70 degrees, and get back to us with your findings.
Also, as for the CO2 thing. The point of it isn't to have higher levels, the point of it is to keep CO2 at normal
levels, so if you are able to keep the CO2 at normal levels at a specific gravity of 1.027 and a temp of 84 degrees, then the CO2 really isn't an issue.
 

ophiura

Active Member
Well, gee I'm sorry.
But what is written in marine biology books applies to the ocean, and the ocean actually doesn't have a great deal of impact on our closed tank systems. I know that doesn't sound quite right, but I can tell you I use very little of my training in marine biology in keeping tanks. It is very different. And you will find in the professional aquarium business (in public aquaria) that many don't want to hire marine biologists because they are so into the books and not what actually happens in closed marine systems. I had an uphill battle in that business.
So they are nice references, but I can definitely say I do not refer to my marine biology books all that often in this hobby.
Sorry if you disagree but you asked for opinions. :notsure: I'll remember to avoid giving them, thanks for your sarcasm, that helps a lot.

BTW, thanks for the slight on the "actual doctorates"....do you know if I have a doctorate? Do you know where I did my graduate research???
I am not sure why you are taking this very personally. But by all means, do whatever you like and let us know how it works out. That would be great. All I gave was an opinion. And you came back with some real nice insults. That's great.
Thanks.
 

hot883

Active Member
Ha! Ophiura, I will listen to every word you say and take it to the bank, or in this case to the tank. I appreciate your real world experience and ability to relate. Thank you for what you do here and thanks for all the advice given to me.
 

alyssia

Active Member
Originally Posted by hot883
Ha! Ophuira, I will listen to every word you say and take it to the bank, or in this case to the tank. I appreciate your real world experience and ability to relate. Thank you for what you do here and thanks for all the advice given to me.


I second that!!!
 

jonnywater

Member
Originally Posted by ophiura
Well, gee I'm sorry.
But what is written in marine biology books applies to the ocean, and the ocean actually doesn't have a great deal of impact on our closed tank systems. I know that doesn't sound quite right, but I can tell you I use very little of my training in marine biology in keeping tanks. It is very different. And you will find in the professional aquarium business (in public aquaria) that many don't want to hire marine biologists because they are so into the books and not what actually happens in closed marine systems. I had an uphill battle in that business.
So they are nice references, but I can definitely say I do not refer to my marine biology books all that often in this hobby.
Sorry if you disagree but you asked for opinions. :notsure: I'll remember to avoid giving them, thanks for your sarcasm, that helps a lot.

BTW, thanks for the slight on the "actual doctorates"....do you know if I have a doctorate? Do you know where I did my graduate research???
I am not sure why you are taking this very personally. But by all means, do whatever you like and let us know how it works out. That would be great. All I gave was an opinion. And you came back with some real nice insults. That's great.
Thanks.

YAWN!!! uh huh. Guess my 6 years of selling marine wholesale specimens has nothing to do with it. ZZZZZZZZZZZZZ
 

jonnywater

Member
Originally Posted by CELACANTHr
Look, there is no need to attack anyone.
If people have had overwhelming success by keeping there tanks at 1.027 and at 82 degrees, and you believe that they aren't doing it properly, then settup a tank with a specific gravity of 1.02, and a temperature of 70 degrees, and get back to us with your findings.
Also, as for the CO2 thing. The point of it isn't to have higher levels, the point of it is to keep CO2 at normal
levels, so if you are able to keep the CO2 at normal levels at a specific gravity of 1.027 and a temp of 84 degrees, then the CO2 really isn't an issue.
Guess Marine Chemistry is wrong then. Sorry about that. <snore>
 

phoenixfla

Member
" I am just saying that if you proof, verify it."
I would think that the person that is suggesting that they may have a better way to do it, would be the one to perform this "experiment". If, in fact, you have better success with a lower temp and a lower SG, maybe it will catch on and change the marine aquarium hobby!
Personally, and I do not mean this as an insult, it sounds like you are attempting to reinvent the wheel. I just can not imagine that someone, somewhere has not had this same idea and followed it through.
I am very interested to see your results, however.
 

squidd

Active Member
There is no arguing the fact that a lower SG will up the CO2 level in a tank and help to stabalize other elements along with calcium and alkalinity. Period.
I'm not a chemistry expert, but I thought CO2 was carbonic acid which in excessive amounts would actually lower pH as it sucks the carbonates and bi-carbonates (alkalinity) out of the water creating an imbalance with calcium which could cause a precipitation event which could drastically affect calcium/alk balance as it falls out of solution...
Not to mention the harmful effect of lower pH on the living organisms...
Co2 is use in calcium reactors to dissolve and release carbonates from a caco3 media... and then when transfered to a higher pH tank become available for corals to assimilate...
Hence the need for a Kalk reactor with it's higher pH to balance the C reactors low pH effluent and supply additional calcium to maintain calcium/alk balance...???
Seems like the additional CO2 would be harmful in a closed tank envrioment...
 
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