Alkalinity goes down ph goes down

[fishRus]

I have a 55 gal with softies and montipora my Alk is 9 and my ph is 8 when my alk goes down to 8 my ph goes to 7.7 I tried dosing with calcium hydroxide to raise my ph but it raised my calcium to over 500 ppm. I add Brightwell KH buffer to raise my alk when it goes down is there any other way to raise my ph Or should I just be happy with 8 ?

 

[Cantusaurus]

8 is decent. I wouldn’t be too upset, but I’d say shoot for 8.1 and 7.9 at the lowest.
It can be difficult for some tanks to get a higher pH. It depends on the setup.
Do you have a sump? And if you do is there a skimmer and or refugium?
Also I wouldn’t dose buffers, they don’t really help past the short term, and aren’t ideal overall in a reef.

 

[Cantusaurus]

Also. Your pH will dictate your Alk level since the higher the pH the faster the growth of corals will be and the more alk will be consumed.
the CO2 in your home plays a big role also and I would check your magnesium level just to make sure that’s in check and not affecting your calcium/alk levels and their balance

 

[Randy Holmes-Farley]

Also. Your pH will dictate your Alk level since the higher the pH the faster the growth of corals will be and the more alk will be consumed.
the CO2 in your home plays a big role also and I would check your magnesium level just to make sure that’s in check and not affecting your calcium/alk levels and their balance

I would argue that while the effect is true that at higher pH there is more demand for alk, it is the alk that determines the pH.

Alk and CO2 together mathematically fix the pH.

 

[sergifed91]

im suffering fro the same thing. I just ran the airline from skimmer to the outside. the ph was way to low for my taste. it got down to 7.7 and i just bit the bullet and ran a test for the past19 hours and stayin at 7.96 happy with it. but would like it to be atleast at 8.0 to 8.1. i don't have any test kits at this time since they all expired. going to a lfs to get mag, ca and alk tested. i think those are off. using fritz blue box.

 

[fishRus]

8 is decent. I wouldn’t be too upset, but I’d say shoot for 8.1 and 7.9 at the lowest.
It can be difficult for some tanks to get a higher pH. It depends on the setup.
Do you have a sump? And if you do is there a skimmer and or refugium?
Also I wouldn’t dose buffers, they don’t really help past the short term, and aren’t ideal overall in a reef.

I am running a canister filter and protein skimmer with outside air and an algae reactor. If I don’t use a buffer what do I use to raise my alkalinity my refill water is a 7. If I use kalkwasser or two part it will raise my calcium to high

 

[fishRus]

I would argue that while the effect is true that at higher pH there is more demand for alk, it is the alk that determines the pH.

Alk and CO2 together mathematically fix the pH.

If CO2 lowers your ph would adding oxygen raise it, like adding an air stone? Is that a benefit of ozone?

 

[sergifed91]

I'm going to continue following this thread. im suffering from low ph also. normmally I use a co2scrubber from may to september. but this year its been fine til august first. dropped down to 7.6 yesterday and just ran an airline to the outside. not 24 hours yet and im thinking it s going to cap out at 8 ppm for my ph. but waiting to see here. what is recommeneded to add for alk that doesn't raise your calcium. if I cause if my test results are correct and im guessing calcium is at 440. but salifert color matching is a little difficult. gping with hanna checkers today

 

[Randy Holmes-Farley]

If CO2 lowers your ph would adding oxygen raise it, like adding an air stone? Is that a benefit of ozone?

Adding oxygen does not impact pH. Removing CO2 does raise pH.

 

[Randy Holmes-Farley]

I am running a canister filter and protein skimmer with outside air and an algae reactor. If I don’t use a buffer what do I use to raise my alkalinity my refill water is a 7. If I use kalkwasser or two part it will raise my calcium to high

Refill water means what? Salt or fresh?



if alk is occasionally low and calcium is always fine, a little sodium bicarbonate or sodium carbonate are good choices to boost alk.

The 7 you mention is pH or Alkalinity?

 

[fishRus]

Refill water means what? Salt or fresh?



if alk is occasionally low and calcium is always fine, a little sodium bicarbonate or sodium carbonate are good choices to boost alk.

The 7 you mention is pH or Alkalinity?

 

[fishRus]

Refill water means what? Salt or fresh?



if alk is occasionally low and calcium is always fine, a little sodium bicarbonate or sodium carbonate are good choices to boost alk.

The 7 you mention is pH or Alkalinity?

Feeling kind of dumb right now but anyway my freshwater alk is 3.5 after mixing instant ocean reef crystals alk it is 12 so I’ve been topping off with water that is 3.5 alk could be why it’s going down the ph of my freshwater is 7
Im using a salifert profi test kit not sure if that works on freshwater

 

[Randy Holmes-Farley]

Feeling kind of dumb right now but anyway my freshwater alk is 3.5 after mixing instant ocean reef crystals alk it is 12 so I’ve been topping off with water that is 3.5 alk could be why it’s going down the ph of my freshwater is 7
Im using a salifert profi test kit not sure if that works on freshwater

The freshwater you use is purified or tap?

It has 3.5 dKH and you use it to replace evaporation? That will steadily boost alk.

The pH of totally pure water is 7.00, but if you add that pH 7.00 water to seawater at pH 8.10, the final pH rises above 8.10. So you should not even think about the pH of fresh water used for top off.

 

[fishRus]

The freshwater you use is purified or tap?

It has 3.5 dKH and you use it to replace evaporation? That will steadily boost alk.

The pH of totally pure water is 7.00, but if you add that pH 7.00 water to seawater at pH 8.10, the final pH rises above 8.10. So you should not even think about the pH of fresh water used for top off.

Very good explanation I think I can manage my alkalinity and PH better now thank you

 

[Cantusaurus]

Very good explanation I think I can manage my alkalinity and PH better now thank you

Yeah, hopefully you have a better idea now. Hope things go well! I had thought pH for a while didn't matter, but even having it at the 8.1-8.2 range makes a huge difference. Corals will be a lot healthier and thicker/stronger too.
And Randy put it very well. Yes, the CO2 causes lower pH. When using a refugium you are taking out the CO2 via macroalgae and doing that at night increases your pH. (I have an all in one tank and with I could have a refugium or algae scrubber, but it is what it is). Making sure Alk is in check is good to make sure pH is good, but also make sure your pH readings are accurate. Having good tank gas exchange helps remove that CO2 from the tank. Also you could try microbubble scrubbing and that can help remove excess organics and may help boost pH a bit (don't expect anything crazy).

You can also just dose Alk supplements to raise your Alk which will increase pH a bit too.
Alk of 7.5 is perfectly fine, but I know most people like to shoot for 8 - 8.5. But as long as it is consistent that is what's important. Alk in the ocean is like anywhere from 6 to 7 I believe.