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I think I murdered my Live rock :(


Chutsk10

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supreme_spork

shame on you, mr. fosi, for bringing science into the discussion.

 

BAD REEFER! your "scientific method" frightens and confuses me... i'm only interested in what joe's brother's friend's sister did that might or might not have worked under a similar or dissimilar circumstance.

 

you just keep your why out of the discussion!

 

:D

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So I don;t want to start a new thread but had 2 more inquiries. . .

 

Is is suggested to still do partial water changes as the tank cycles or do I just leave it alone until it's done?

 

Also, after testing the water and if I find the salinity is low, can I add salt mix directly to the aquarium or do I have to premix it and then add it as a solution?

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supreme_spork
So I don;t want to start a new thread but had 2 more inquiries. . .

 

Is is suggested to still do partial water changes as the tank cycles or do I just leave it alone until it's done?

 

Also, after testing the water and if I find the salinity is low, can I add salt mix directly to the aquarium or do I have to premix it and then add it as a solution?

 

 

for your first point, you'll find about 50-50 split on this topic. if you do partial water changes during your cycle -- a "soft cycle" -- you'll keep more stuff alive but it will take a bit longer to complete. definitely read mranderson's experiment thread for an example of what's possible with soft cycling -- i wouldn't do it any other way.

 

no, never add salt mix directly to your tank, always premix and add as solution that's the correct specific gravity and temperature.

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Great info Mr. Fosi. My question is what is the 02 level of RO? Is it the same as water from the ocean? Not trying to nitpick, just very interested.

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shame on you, mr. fosi, for bringing science into the discussion.

 

BAD REEFER! your "scientific method" frightens and confuses me... i'm only interested in what joe's brother's friend's sister did that might or might not have worked under a similar or dissimilar circumstance.

 

you just keep your why out of the discussion!

 

:D

Your sarcasm is pointless. Noone asked him to keep science out of it. What a waste of bandwidth.

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Those are some tangible results, but again, I think those results are unique to your situation. It is hard to say what would happen w/ different brands of salt or different types of water.

 

You made the observation of the IO salt dissolving in 10-15 minutes, while I can wake up the next morning after mixing a bucket of salt and still see salt in the bottom of the bucket (even w/ a powerhead). The chemistry of the water on the west coast (especially in the rocky mountains) is different than that on the east coast. There could be variation just based on ro/di vs tap water too.

 

I guess it just comes down to not enough being known.

 

In that case though, all I have to go on is my own experience and customer feedback. I personally have no reason to question whether or not the 24 hour methods works, however, I do question less than say 6 hours of mixing. I can not prove it was the saltwater being used directly after mixing that has caused the problems I have observed/been informed of, but that a question remains as to whether it is safe or not leads me to continue recommending people mix their water for 24 hours when possible, and as long as possible when emergency water changes are needed.

 

Additionally, Instant Ocean has been in the salt game for a long time. I'm sure they've extensively tested their product to see how to get the best performance out of it. I don't think they would just blindly make the recommendation on their website that their salt be mixed for 24 hours with out having some serious analysis behind it.

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no, never add salt mix directly to your tank, always premix and add as solution that's the correct specific gravity and temperature.

 

What if the salinity just has to be raised a little bit. . . the water would have to be removed form the tank (to make rom for new water) and then I would have to mix some with a higher salinity than I want to achieve since it will dilute when mixed into the tank. . . . I must be missing something here. . .

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The probe doesn't really measure the concentration of O2, it measures the partial pressure of O2. That means that it will tell you what percentage of the dissolved gas is oxygen. If you want the concentration, you need to know the temperature of the water and 1 or 2 other bits of info.

 

In the case of the the graph I presented, you'll notice that the baseline %O2 is ~21%, which it should be since ~21% of our atmosphere is O2. So in this sense, the O2 level of the RO is exactly the same as the salt water but may or may not be the same as the ocean.

 

In the ocean, it is possible to get supersaturation of O2 above ambient atmospheric levels but you only see that when the water is choppy and injected bubbles get mixed down a few meters where the pressure compresses them into solution. However, even in that solution, you won't see the %O2 change much if at all because all the gasses in the injected bubbles (i.e. typical air proportions) get pushed into solution equally.

 

Gas concentration in the ocean is really tricky because it involves several variables, all of which will greatly change your calculated value. That is one reason that it can be advantageous to measure %O2.

 

Green: I don't think you are seeing salt. If your IO is like mine, you are seeing precipitated CaCO3. Do a little experiment. Pull out the "salt" that is in the bottom of the bucket and try to dissolve it in freshwater. It won't go because it isn't salt. If you try dissolving it in soda water or another acidic solution, it'll go right into solution because it's CaCO3. If you still don't buy my explanation, see if you can talk a chemist into running it through a GC.

 

The CaCO3 precipitates because we add it too quickly and there isn't enough CO2 in the water to keep the Ca2+ and the CO32- in solution. If you bubble some CO2 through the water it'd go right back into solution. I know because I have done this.

 

Chuts: Never add salt directly to your tank. If you need to raise the SG for some reason, do it slowly and do it by doing water changes with water that is a slightly higher SG.

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Thanks Mr. Fosi! Now I know what's in my bucket for so long. The O2 info makes good sense. I learn something new here all the time :)

 

So, it is safe to say that your way is okay but waiting 24 hour could allow for more O2 saturation? Perhaps that is what the manufacturer of IO had in mind?

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So, it is safe to say that your way is okay but waiting 24 hour could allow for more O2 saturation? Perhaps that is what the manufacturer of IO had in mind?

 

Could be, but I am not sure why you would need that. If your water is in equilibrium with the air in the room (which it will be very soon after you finish adding salt), then you have plenty.

 

Also, lgreen, there is a wealth of primary lit out there on oxygen probes based on fluorescence quenching that show the theory that predicts the exact results I found and they hold true for solutions of any ionic strength. Therefore, I feel very comfortable saying that salt brand makes no difference whatsoever.

 

If you really need me to, I'll go dig for some papers but I don't really want to since you can look them up and prove it to yourself.

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I feel bad about not providing any citations so here is one:

 

Reimers CE, Shahriari MR, Wainright SC, and Wang W (1997). A sol-gel based fiber optic sensor for monitoring dissolved oxygen in marine environments. Proceedings of the Marc’h Mor Workshop IUEM in Brest, France. November 17-19.

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Saltwater is a fairly complex solution...we both know that. I don't see how just looking at the partial pressure of oxygen provides a comprehensive enough base to come to any overall conclusion, considering there is so much more going on than just the equilibration of oxygen.

 

I mean, I'm surprised you've come to the conclusion you have with such little evidence, really.

 

We can look at the chemistry all we want, but is that really going to tell us what happens in real life? I'd propose a better experiment for answering this question include exposing urchin larvae to saltwater than has been allowed to age for different amounts of time. Duplicates and a nsw control. Then if differences are observed, we can ask why.

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PLEASE!! THIS IS NOT AN ATTACK OR FLAME OR WHATHAVEYOU...

 

I read a few acticles and books, including The Conscientious Marine Aquarist and The new Marine Aquarium before I started, and the method of aging SW was recommended due to pH stabilization. I have heard the same thing from others, and have done so with my tank. The graph dealing with O2 makes good sense, I was just under the impression that pH was a contributing factor in freshly mixed SW...

 

"Anyway the question really is your opinion on the pH fluctuating. I do 10% water changes weekly...using RO

<hmmm... hoping the RO water is first heavily aerated (24+ hours to raise the pH and drive off carbonic acid/CO2) then re-mineralized (buffered) and mixed (12+ hours) and only then considered for use as evap top-off or salted for seawater). Else you have a source of your pH instability (weakly buffered source water)>" -from WetWebMedia

 

Help?

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^haha very funny.

 

sigh, reef humor... :rolleyes:

 

Hey, I'm planning a baby urchin tank :P

 

A study has already been done and talked about here somewhere. Synthetic salt effected the study group so much I don't think anything conclusive could be decided anyway.

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holdorf:

 

well, pH is a direct function of CO2 concentration, and Mr. Fosi was saying that equilibration with atmospheric CO2 is likely to occur at a similar rate ("similar" being less than an order of magnitude, or 10 x whatever timeframe) as oxygen. since the published and experimental data for O2 equilibration is along the lines of a few minutes, he's extrapolating that CO2 shouldn't be much more.

 

the methods cited are the standard for this type of study, not sea urchin eggs. methods require validation as well, coming up with new assays only confounds the issue. but i thought lgreen was making fun of Ron Shimek's silly salt study, so i don't think he was serious.

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holdorf:

well, pH is a direct function of CO2 concentration, and Mr. Fosi was saying that equilibration with atmospheric CO2 is likely to occur at a similar rate ("similar" being less than an order of magnitude, or 10 x whatever timeframe) as oxygen. since the published and experimental data for O2 equilibration is along the lines of a few minutes, he's extrapolating that CO2 shouldn't be much more.

Gotcha. So the idea being that O2 concentrations could have a direct corilation on CO2 levels at the time of introduction to RO, and thus rise at the same rate. CO2 levels being similar to atmospheric levels, the time required to "settle" would be nil. ...right?

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What if the salinity just has to be raised a little bit. . . the water would have to be removed form the tank (to make rom for new water) and then I would have to mix some with a higher salinity than I want to achieve since it will dilute when mixed into the tank. . . . I must be missing something here. . .

 

 

you all have completely hijacked this poor persons thread. They had this small question they wanted answered.

 

Maybe someone could answer it, and start a thread somewhere else to discuss how long to premix salt?????

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