Low Ph 7.59 using calcium reactor

If you use kalk, you will basically have to balance the ca reactor usage with the kalk until you get into a decent pH range. Definitely try a different probe, however, probes when they go bad tend to become hard to calibrate. They don't calibrate easily, and then read low in your tank. In other words, if you calibrate with pH 7 solution, then 10, and then go back to 7 it should still read about 7 and then is you go back to 10, it should read 10. Does it?


As you kalk+2, I am not sure what the miscommunication was, or if you were talking to someone who knew anything about kalk. All calcium-hydroxide raises pH. It does discuss elevated pH on their website too. Kalk+2 will not raise mg however, as mg can not dissolve in high pH solutions, such as saturated lime-water, as it will precipitates out of solution. This has been shown and discussed often by Randy Holmes-Farly, yet Brightwell continues to advertise it. It's also been shown that mg is an impurity in most kalk anyways, yet they advertise it as a feature. Just be aware of this if you are expecting it to help your mg...

 

hey m2434 guess they should rename it kalk+1 ;D but you are correct, i use kalk+2 and have to dose mag. i do like how fast it mixes and settles so i have not switched for that reason.

im guessing there was a misunderstanding at brightwells with the calcium and kalk


hey thang45 do you run your gfo and carbon in a reactor? if not doing so might help with that algae problem it wiped mine out

 

You know what I have never retested after I calibrated. So I can consider the probe bad if it doesn't say close to 7 in a 7 solution?

I told him about it too but he said he has never heard of it of using kalk to raise the pH.

Yes I have GFO, last month I added 500mL and my PO4 from the reactor is under 0.10ppm.

My mg is low right now, so I'm adding Tech-M to raise the mg. Hopefully when it reaches 1350 -1400 I can start added other buffers.

 

Yes, calibrate with ph 7 solution, then ph 10, then put back in 7 and make sure it goes back to very close to 7 (i.e. 7.1 would probably be okay, but not 7.5 or 6.5 etc..). Then put back in 10pH solution and make sure it's close to 10. Also, make sure to rinse the probe in RO/DI water before transferring to any solution.

I just have no idea what to say about that. Either there was a misunderstanding, or you are talking to someone that does not have any idea what he's talking about.

here is a good article from a well respected chemist: Low pH: Causes and Cures by Randy Holmes-Farley - Reefkeeping.com

The entire article is great, and you should read it, but also, make sure to see the sections "Solutions to pH Problems" and "Low pH due to CaCO[SIZE=-1]3[/SIZE]/CO[SIZE=-1]2[/SIZE] Reactors"

I'm not sure I understand this comment. The term "buffer" in our hobby refers to an alkalinity suplement. The limewater and ca reactor add all the alkalinity you will need and you will have to monitor them to make sure you are not adding too much. Too much can kill stuff and cause a lot of issues. So, you shouldn't be adding more buffer. Even with a mg level of 1200, you should be able to raise your alkalinity up to about 11. After that, you may start to have issues. Your pH problems though are due to CO2. You mainly need to focus on reducing CO2, not adding alk so much. You should be able to maintain a decent pH with any alk level between 8 and 11 really.

Randy's article provides more detail, please read.

 

Yes I mentioned about that article but he said he has been doing this for 5 yrs and did not know people are using it to raise the pH. I did asked him to confirm this info with others in the company.


What I meant to say is that I need to bring up my mg to 1350-1400ppm range before adding other additive such as alk and cal. Others have told me that if mg is below 1350 pH, alk and cal will not be stable. Maybe I've missed something here.

 

A quick Internet search would show raising pH is the primary reason people use kalk vs other calcium/alkalinity supplements LOL.

Also by the way Bulk Reef Supply sells USP grade ("medical grade") kalk for ~1/4 of the price. You can also get Mr Wages Pickling lime, which is a food grade kalk for even less.

As to adding calcium and alkalinity supplements, that is what a calcium reactor and kalkawasser does. These are methods of supplementing ca and alk. What magnesium does is prevent calcium and bicarbonate ("alkalinity") from chemically binding and forming calcium-carbonate crystals (more or less limestone). However, ca and alk are pretty stable with mg levels above about 1200ish. I think higher is better for a number of reasons though, but it shouldn't have enough of an effect to be causing your pH issues. Plus you already stated your ca and alk levels were within the desired range (I.e. "stable"). If you mg was too low, this wouldn't be the case. Raising mg is desirable though, but it's not the direct solution to your current issues.


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Thank you very much for this great explanation. This morning I noticed another big colony is getting white tip. I think it is dying.
My pH this morning is at 7.7 and I think my cal and alk are not balance. I will do a complete test for ca, alk, mg, po, nitrate and will post the results tonight, hopefully you guys can pinpoint what is wrong.
Anyway, I was looking for pH buffer and everything I saw so far are using alk to raise the pH. So pH buffer is nothing more than adding alk?
If calcium reactor and kalk are methods of supplementing ca and alk then I should only stick with one method correct?

 

No problem, white tips are typically either a sign of growth or die-off. It depends if there are polyps and tissue remaining. In the case due to what you have described, it is probably die-off, as you expect. We call this type of die-off "burnt tips" and it results from raising the alkalinity too much or too fast. As you are trying to raise the alk to avoid low pH this is almost certainly the case. You need to be careful with alk, it is actually much more important than pH.

As to the pH buffer you will not find one that does not raise alkalinity. As mentioned, there are only two ways to raise pH. 1) to raise alkalinity and 2) to lower CO2.

Kalk is effective because it adds alkalinity and reduces CO2.

A calcium reactor adds alkalinity, but adds CO2

Other "buffers" generally add alkalinity and have no effect on CO2. The term buffer is misleading and should not be used in my opinion. It is not a "buffer" it is a alkalinity supplement. Alkalinity is basically the ability of the water to neutralize acids. So, in this sense it is sort of a buffer because it will help prevent sudden drops due to increased acidity. However, it is not a "buffer" in the way some manufactures would lead you to believe. It has not special relationship to pH 8.3 for example. That is a completely arbitrary number, for marketing purposes.

The reason we are interested in alkalinity is it is a source of inorganic carbon, needed for coral growth. In water there are 3 species of inorganic carbon. CO2, carbonate and bicarbonate. The 3 can interchange based primarily on pH (although note CO2 doesn't effect total alkalinity, but does lower pH) Inorganic carbon is needed for coral skeletal growth and is the primary component of alkalinity, but we can't test for it directly, so we measure alkalinity instead. Also, corals seem to preferentially use bicarbonate.

And for CO2 while corals may be able to use it, paradoxically, it lowers pH, which if too low, can prevent corals from using it (and if really low can dissolve the corals altogether). So, we need to balance alkalinity with CO2, but this gets difficult especially when adding CO2 with calcium reactor. It you can bleed off that CO2 as it enters the aquarium though, it is less of an issue. This is why I suggested running an airline out of a window. Outside there is less CO2, so, the partial pressure of CO2 is lower and there is less force pushing more CO2 into the water. Especially utilizing the skimmer, as there is a lot of bubbles (I.e. Surface area) in the skimmer compartment for gas exchange. So, the CO2 goes out, rather than getting trapped in. Also this can be accomplished if you can somehow reduce CO2 in your house, maybe by opening a window, but that may not be desirable...

Kalk will also lower CO2, but will also add alk . This also may not be desirable in your case, especially as your already seeing burnt tips.




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Wonderful info! And may I commend you on your impressive use of the iPhone key pad LOL

 

LOL +1 on above ;D