Boomer

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That is a fairly good assessment but has some errors that he is not familiar with. His table is off, as for when you are trying to give real CO2 levels you have to use the real pH of seawater, which we do not use, nor does his table. There are 3 pH scales for seawater, ie, pH-nbs, pH-t and pH-sws. We use pH-nbs which gives pH levels that are ~ 0.15 pH to high. Nothing you guys need to worry about. We often tell you guys the pH of seawater is around 8.3, what you look for on your meter but the real pH is ~ 8.15. Even seawater text books use to give the pH-nbs, till just recently. With this ^ said DO NOT race off telling people your pH is wrong and you need to fix it. We have already fixed it for you by telling you NSW pH is 8.3. So, you subtract that 0.15 from 8.3 and you get what NSW @ 8.15 real pH, same pH.

Also, the remark on calcium carbonate dissolving is so low it can not even be measured. So, there is no sense in mentioning it. It is pretty much a myth the sand dissolves, been proven many times it does not.

Also, as I already stated, CO2 has nil effect on Alk and can be proven. He also makes no mention of the real issue with low pH for many, high room air CO2.

He is writing is good stuff but does not really fully understand what he is saying. Meaning, he is saying low pH is only a photosynthesis issue between day and night. He has no mention of high room air CO2. As far as day and night fluctuations in your tank, well, many do not realize this but reefs also have day and night fluctuations in pH.

This what I mean by is error in the table

If it were 7.7, then your tank would have 5.3 times the CO2 of NSW

At his dKH of 9.8 and his 1:1 pH 8.3

CO2 = .58, pH 8.3, Alk 9.8 dKH

CO2 = 2.83, pH 7.7, Alk 9.8 dKH

2.83 / .58 = 4.88 x, NOT 5.3 x as his table shows.

And that .58 and 2.83 = 0.58 ppm CO2 and 2.83 ppm CO2

But the guy means good he us just off target. With the errors fixed it would be a nice piece. This always happens when one uses freshwater std / measurements and you are dealing with seawater.





Your comment

I would like to make an experiment to set up a new fish tank, with less fish and corals. To see if theres any difference in the PH in the same room. Do you think there will be a difference ?!. Thank You.

Yes, it may, depending on the amount of CO2 being generated in the high density tank vs the low density tank. CO2 enters water very easily but is harder to remove. Equilibrium with the air is not instant. You can generated CO2 in the tank faster than it can be removed = low pH, common in high density fish tanks. Heavily planted tanks can remove CO2 faster than it enters the tank from the air = high pH, why they add CO2 to lowers pH

If one does allot of water changes and you have no or very littler high room air CO2 the tank will be more stable. A friend of mine does a 100 % WC every 2 weeks but the salt and water are FREE.

The real issue with most reefers is for some odd reason they like to chase numbers. People need to learn if you are within the excepted range of parameters leave the dam tank alone. Meaning, some guy has to have his dKH @ 10 and 9.8 is just wrong in his mind.
 
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vio

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You, 110% right.

"The real issue with most reefers is for some odd reason they like to chase numbers. People need to learn if you are within the excepted range of parameters leave the dam tank alone. Meaning, some guy has to have his dKH @ 10 and 9.8 is just wrong in his mind."


I just check my PH now, is 7.97 i use American Marine Pinpoint pH Controller , i was ready to buy this:

http://www.ebay.com/itm/Molecular-P...858?pt=LH_DefaultDomain_0&hash=item5d3d8e84fa
__________________
 

vio

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What is the high and low for the day. Measure it tomorrow afternoon if you can. If you get no lower than that 7.97 in 24 hrs leave it alone.



if I remember correctly, day is 8.03 to 8.05, I thing I have to add a small Koralia pump, right under Protein Skimmer stand, I see detritus precipitation.
 

Dan_P

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Dan

There are a number of ways that will make a big difference on removing excessive CO2.

1. A line to the skimmer air from outside air.

2. A Granular Kalk CO2 Scrubber. A DI type or PVC pipe containing the granular Kalk. The air is run through the container and the CO2 and moisture reacts with the Kalk converting the Kalk from Calcium hydroxide to Calcium Carbonate.

3. A Sodium carbonate or Sodium hydroxide liquid CO2 Scrubber. A 5 gal bucket with the solution. Your air tube goes to the bottom. The out tube is under the lid. The air bubbles rise through through the solution removing the CO2 as it rises to the surface under the lid, where the lid tube pushes it out under accumulated pressure.

4. 2 PVC or plastic tubes, where one pulls in outside air and blows it across say the right end of the tank and another tube on the left end to the outside that sucks the CO2 to the outside. You need two fans, one a pulling fan, pulling in outside air and one a pushing fan, pushing the air outside. Best on tanks with cover lids. Open tanks won't do much.

Theses methods are all proven and can raise the pH from 0.2- 0.4 pH units in low pH tanks. Remember these are all from high room air CO2. High tank generated CO2, usually a rare issue but does happen in dirty/ over fed tanks, is a different issue.

To say it again, people, as Dan put it "you can not effectively raise the pH by increasing the alkalinity" When you try this the pH does rise, as does the Alk. The CO2 re- enters the tank, the pH drops. You do it again and again and what happens ? The same. The pH goes back to the same and now your Alk is through the roof. Adding buffers does nothing for low pH issues from CO2. Meaning, increasing or decreasing the CO2 does not change the Alk. You can prove this with a glass of water and a pH meter or kit when you blow air into the glass with a straw. The pH will drop the Alk will not change. And adding Kalk to the water is a little different as it reacts with the CO2 giving bicarbonate, a buffer.

Ca(OH)2 + 2CO2 -----> + 2HCO3- + Ca--

Thanks Boomer. These are very practical ideas and seem straightforward to implement.
 

Boomer

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I would leave it alone par removing the detritus. Your daily flux is only ~ 0.05 pH. As I said the real pH of the ocean is 8.15, so we want the meter to read 8.3. However, to be more realistic, such as were most of out marine live comes from, that real pH is not 8.15 but 8.05. So, add that correct error of metes of 0.15, you would want your meter to read NOT 8.3 but 8.2. So, you are just a bit over 0.1 low. If you can get it up, NO drastic measures, fine, otherwise leave a good thing alone.

If you give me your Alk I can tell what your pH should be if you had zero CO2 issues compared to the ocean. If you had normal coral reef Alk, CA ( No Borate Alk) = ~ 2.25 meq/l, 80F @ 35 ppt it would be 8.2 <-- what your meter should read. If we raised that CA ( No Borate Alk) Alk to 2.75 meq/l, then 8.27 pH.

CA = TA (Total Alk) - BA ( Borate Alk). On the avg BA gives ~ 0.1 meq / to a TA of 2.35 meq/l. So, 2.35 meq/l TA - 0.1 BA = 2.25 CA.

So, I would have to guess your BA. Meaning, if you do normal WC your BA would be ~ 5% of the TA. With no WC the BA would be 0 %.
 

vio

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Wow, last test of Alk. was 143 ppm (8.oo8 dKH) and I dose Kalkwasser like 10 mil. a day, I have Deltec KM500S Kalkwasser Stirrer, I add 2 cups (Kalk) for 2.5 USGal. RO/DI.


Ca.=425
Alk=8.008 dKH
Mag. =1350
Sal. =1.026 (Thank's to you, my refractometer was off, I order the new one)
Temp. 78 F
PO4 .003 (I try to keep like that)
Nitrate 0
CO2 on basement 500-600 ppm (better then my bedroom) outside 430 ppm (New York).
150 Gal.tank + 60 gal.sump
20 gal. water change every week (ESV) Thank You.
 
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Boomer

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CO2 is 500-600 ppm. Normal country air or the ocean is ~390 ppm.

Ok, pH with that avg 550 ppm CO2, Alk 8 dKH

pH should be 8.27 meter reading

Now with CO2 @ 390 ppm, should be 8.15, meter reading. Some house are much higher than yours.

So, your issue is that high room air CO2, dropping your pH 0.1 lower than it should be. Not much to worry about.

Your tank has about 0.7 - 1 ppm CO2 and should have 0.5 ppm CO2 <-- if the ocean
 
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