pH and kH new issues with new salt

[SOGavity]

Over the last year I've struggled with hair algae and coral growth. All parameters were met for coral growth except my nitrates were very high (which is what probably fueled the algae growth). But the aglae I could deal with. It's the non-growing corals that were bugging me. My very first coral was a candy cane that I bought with two heads. And it still has only two heads a year later. Now, where I'm from, there are two salt choices. Instant Ocean or Red Sea Salt. I started with Instant Ocean because it the only salt within 44km. But after doing some research and thinking it's the pH that is fueling both issues, I drove 45 minutes to pick up a bucket of Red Sea Coral Pro........ and a new fish tank......

This new 87 gallon tank came with a 30 gallon sump and a coupon for a Bubble Magnus protien skimmer. How could I not? After setting it up, adding a whole bunch of rock from my old tank and filter media, I felt good to go. (I didn't add fish or anything yet, we'll get to that).

After filling the tank with Coral Pro salt, I tested the tank and received these readings...

1.026 Salinity
0 ammonia
0 Nitrites
5 nitrates
.02 phosphates
15 kH
and pH was so high, my hanna tester just blinked 8.6 at me with confusion. So used my trusty API tester and the reading was inconclusive as the purple it changed to wasn't on the chart.

I've left it to cycle and do it's thing because even though I used old media, I used 100% new water and just wanted to give it a chance. Now, it's been 15 days and the only thing that changed was my phosphates which moved up to .05. Everything else is the same. Still can't read that darn pH level.

So now what do I do? Using the Instant Ocean gives me a pH of 7.8-8 and a kH of 8. I swear I'll never find a perfect medium. I do not dose anything... never had to. Magnisium in my first tank has always stayed 1410 and calcium 420. It never seems to be used in my old tank dispite having a large number of corals.

 

[fishyjoes]

Your ph is likely suppressed by CO2 - but that probably doesn't matter to your corals anyway.

I use instant ocean, and when my house is all closed up my ph goes down to ~7.8 like yours. If I can have the windows open all day my ph will go over 8.2 (I've seen as high as 8.43, measured with pinpoint ph monitor calibrated monthly).

I have several different candy cane corals - they all started with two heads somewhere around 1.5 years ago (I didnt' get them all at the same time). Currently one has six heads, one has four heads, and one still has the same old two heads.

Do you have any other corals? If so, how are they doing? If not, you may want to try a few different kinds.
I have been surprised by which corals do well for me and which do not.

 

[KrisReef]

I wouldn't expect pH to inhibit coral growth that much over a year.

reading again Ii think you are discussion Alkalinity, (dKh 15 now?)

Back when I had a Duncan frag I let it catch (a lot) of drifting fish food when I fed. Tank pH hovered around 8.0, with 7.8 not being uncommon I keep Alk close to 8.0 also, and I am very careful to have Alk not bouncing around like my pH does. Stable Alk grows corals over time. Elevated dKh caused issues with calcium carbonate deposition in pumps when I tried to keep it high.

I also wonder if your duncans need more light?

 

[Randy Holmes-Farley Verified Community Expert]

Over the last year I've struggled with hair algae and coral growth. All parameters were met for coral growth except my nitrates were very high (which is what probably fueled the algae growth). But the aglae I could deal with. It's the non-growing corals that were bugging me. My very first coral was a candy cane that I bought with two heads. And it still has only two heads a year later. Now, where I'm from, there are two salt choices. Instant Ocean or Red Sea Salt. I started with Instant Ocean because it the only salt within 44km. But after doing some research and thinking it's the pH that is fueling both issues, I drove 45 minutes to pick up a bucket of Red Sea Coral Pro........ and a new fish tank......

This new 87 gallon tank came with a 30 gallon sump and a coupon for a Bubble Magnus protien skimmer. How could I not? After setting it up, adding a whole bunch of rock from my old tank and filter media, I felt good to go. (I didn't add fish or anything yet, we'll get to that).

After filling the tank with Coral Pro salt, I tested the tank and received these readings...

1.026 Salinity
0 ammonia
0 Nitrites
5 nitrates
.02 phosphates
15 kH
and pH was so high, my hanna tester just blinked 8.6 at me with confusion. So used my trusty API tester and the reading was inconclusive as the purple it changed to wasn't on the chart.

I've left it to cycle and do it's thing because even though I used old media, I used 100% new water and just wanted to give it a chance. Now, it's been 15 days and the only thing that changed was my phosphates which moved up to .05. Everything else is the same. Still can't read that darn pH level.

So now what do I do? Using the Instant Ocean gives me a pH of 7.8-8 and a kH of 8. I swear I'll never find a perfect medium. I do not dose anything... never had to. Magnisium in my first tank has always stayed 1410 and calcium 420. It never seems to be used in my old tank dispite having a large number of corals.

Can you clarify exactly what you are concerned about? I'm not seeing a problem. pH is not a concern.

Coral Pro is a very high alk mix. If you want it lower, you can lower it with an acid or water changes with a lower alk mix, but I see no reason to at the moment. It will decline on its own.

 

[SOGavity]

Your ph is likely suppressed by CO2 - but that probably doesn't matter to your corals anyway.

I use instant ocean, and when my house is all closed up my ph goes down to ~7.8 like yours. If I can have the windows open all day my ph will go over 8.2 (I've seen as high as 8.43, measured with pinpoint ph monitor calibrated monthly).

I have several different candy cane corals - they all started with two heads somewhere around 1.5 years ago (I didnt' get them all at the same time). Currently one has six heads, one has four heads, and one still has the same old two heads.

Do you have any other corals? If so, how are they doing? If not, you may want to try a few different kinds.
I have been surprised by which corals do well for me and which do not.

I do have other corals and they have not grown either. I used my candy cane as an example because it's my oldest. The other corals I cant quite remember when I got them all. I have 3 hammers, octospawn, frogspawn, duncan, birdsnest, fuzzy mushrooms, discoma mushroom, 2 cyphastreas, zoas (also my oldest and haven't grown a single polyp), purple trumpet coral..... I think that's all, and all I'm going to have. They are all healthy and beautiful with no growth.

Also, I live in Canada where it's too cold to open windows. I have purchased a co2 scrubber and waiting for it in the mail.

 

[SOGavity]

I wouldn't expect pH to inhibit coral growth that much over a year.

reading again Ii think you are discussion Alkalinity, (dKh 15 now?)

Back when I had a Duncan frag I let it catch (a lot) of drifting fish food when I fed. Tank pH hovered around 8.0, with 7.8 not being uncommon I keep Alk close to 8.0 also, and I am very careful to have Alk not bouncing around like my pH does. Stable Alk grows corals over time. Elevated dKh caused issues with calcium carbonate deposition in pumps when I tried to keep it high.

I also wonder if your duncans need more light?

I have fed some corals directly. I don't do it too often because of the nitrate level I have. Everywhere I've read says 8.3 ph grows best.

 

[KrisReef]

I have fed some corals directly. I don't do it too often because of the nitrate level I have. Everywhere I've read says 8.3 ph grows best.

I have read the same thing.

I have not tried to keep in elevated but just run it where it wants to be with reasonable results. Trying to get it in line and stable at the elevated number would probably require me to add a Kalkwasser reator to supplement my Calcium Reator. I'm not trying to grow for profit and so I accept any growth reduction that may be happening from the lower pH number.

 

[rishma]

I don’t think pH of freshly mixed saltwater is something to worry about or chose a salt based on. In general it will be at equilibrium with the CO2 in the water/air as a function of the alkalinity.

Your alkalinity is exceptionally high. In the old days I kept it as high as 12 dKH but these days I keep between 8-9. I think 7-11 is generally accepted as a good range.

Lots of things can impact growth. Water flow, light, nutrients (N,P), major and minor elements, etc. it’s hard to tell what is limiting in your case.

 

[rishma]

Here is a handy chart from one of Randy’s articles. With your alkalinity at 15 dKH (5.3 meq) you can see where your pH likely falls.