Low pH, high calcium, lower Alk

[Shawn4455]

Hello. Started up a Red Sea reefer 525 XL, I have several frags in it and lately I've noticed my numbers have been trending down.

My pH no longer goes above 7.75 my alkalinity has been steadily dropping it is currently 7.2, and my calcium is anywhere between 450 and 470

I went ahead and invested in a refugium and bought some sea lettuce and a nice fuge light, which helps with keeping it stable, but I used to hit 7.8-7.9. I do 10% water changes every week with the Red Sea black bucket which helps a little but 10% is not much.

I'm not sure what else I can do... Any other info I can provide to help you guys help me ?

 

[arking_mark]

I also run a Reefer 525xl. Great tank.

How old is the tank?

What are you dosing?

How are you measuring pH, Alk, and Ca?

Generally speaking:
- pH is usually low due to higher CO2 levels in your home
- Your tank will consume 0.5 dKHto 4.5 dKH per week (and a equivalent 3.5ppm to 30ppm Ca)
- Water changes will not be able to keep up with consumption unless your using a high-parameter salt.

There are several ways to increase pH and several more ways to keep up with Ca/Alk demand.

Many here (including myself) drip Kalkwasser to boost pH and provide balanced Ca/Alk dosing. Kalkwasser can only be dosed to your evaporation limit and you will have to eventually dose something else once you demand exceeds this.

 

[Shawn4455]

I also run a Reefer 525xl. Great tank.

How old is the tank?

What are you dosing?

How are you measuring pH, Alk, and Ca?

Generally speaking:
- pH is usually low due to higher CO2 levels in your home
- Your tank will consume 0.5 dKHto 4.5 dKH per week (and a equivalent 3.5ppm to 30ppm Ca)
- Water changes will not be able to keep up with consumption unless your using a high-parameter salt.

There are several ways to increase pH and several more ways to keep up with Ca/Alk demand.

Many here (including myself) drip Kalkwasser to boost pH and provide balanced Ca/Alk dosing. Kalkwasser can only be dosed to your evaporation limit and you will have to eventually dose something else once you demand exceeds this.

The tank is relatively new. Maybe about 7 months now. I have sever corals as well as several fish. Which all seem to be doing OK. The more sensitive corals like my torches get a little closed when the pH is like this but still open and happy. I'm now just starting to get Coraline.

My last alk was 7.3 and Ca 493, I wouldn't mind dosing kalk, but I thought kalk increases calcium as well.

Do you think dosing kh/alk from redsea to help drive down the calcium and increase pH and alk help to stabilize?

I also have a CO2 scrubber coming in and I'm going to try doing the recirculating method with my skimmer

 

[arking_mark]

The tank is relatively new. Maybe about 7 months now. I have sever corals as well as several fish. Which all seem to be doing OK. The more sensitive corals like my torches get a little closed when the pH is like this but still open and happy. I'm now just starting to get Coraline.

My last alk was 7.3 and Ca 493, I wouldn't mind dosing kalk, but I thought kalk increases calcium as well.

Do you think dosing kh/alk from redsea to help drive down the calcium and increase pH and alk help to stabilize?

I also have a CO2 scrubber coming in and I'm going to try doing the recirculating method with my skimmer

Generally speaking Ca/Alk are consumed almost equally in a reef aquarium. Ca tests are pretty inaccurate and prone to errors. So I'm not sure I'd trust your measurement. However, Ca is very plentiful and not as critical. So if your Ca has creeped up due to dosing or some imbalance that was introduced, you can just use baking soda (or other methods) to raise your Alk. As a general rule of thumb, I usually never raise alk by more than 0.25 per dose for a total of 1dKH per day.

This reef calculator can help with dosing:

Reef Chemistry Calculator

As to using a CO2 scrubber, this might be of interest to you:

Tuning a Skimmer / CO2 Scrubber for pH Control

On my reefing journey, I found Kalkwasse + Skimmer + CO2 Scrubber to be very effective for bringing my pH from 7.8 - 7.9 to 8.26 - 8.36. I guess most people would just leave it at that. However, I wanted to be more efficient with the CO2 scrubbing material so I wanted to implement a...

www.reef2reef.com

 

[Shawn4455]

Generally speaking Ca/Alk are consumed almost equally in a reef aquarium. Ca tests are pretty inaccurate and prone to errors. So I'm not sure I'd trust your measurement. However, Ca is very plentiful and not as critical. So if your Ca has creeped up due to dosing or some imbalance that was introduced, you can just use baking soda (or other methods) to raise your Alk. As a general rule of thumb, I usually never raise alk by more than 0.25 per dose for a total of 1dKH per day.

This reef calculator can help with dosing:

Reef Chemistry Calculator

As to using a CO2 scrubber, this might be of interest to you:

Tuning a Skimmer / CO2 Scrubber for pH Control

On my reefing journey, I found Kalkwasse + Skimmer + CO2 Scrubber to be very effective for bringing my pH from 7.8 - 7.9 to 8.26 - 8.36. I guess most people would just leave it at that. However, I wanted to be more efficient with the CO2 scrubbing material so I wanted to implement a...

www.reef2reef.com

I used my local shop's testing which they use the API spin, would high calcium generally hurt anything in the tank? I increase aeration in my tank which did help tremendously but slowly went down, now its at 7.63, I tried opening the doors at night which didn't help very much. I have a co2 scrubber on the way but won't get here until mid-this week. The corals seem to find so far, not that closed, but not that open either. if I test my alk if I start dosing alk or kalk can I overdose causing calcium to go crazy?

To my understanding increasing, alk should increase pH, right? Even if I am not using Kalkwasser? Or is it the calcium buffering causing the pH to rise and has nothing to do with alk?

 

[Randy Holmes-Farley Verified Community Expert]

I used my local shop's testing which they use the API spin, would high calcium generally hurt anything in the tank?

IMO, if calcium is not over 550 ppm, it's no concern.

 

[arking_mark]

I used my local shop's testing which they use the API spin, would high calcium generally hurt anything in the tank? I increase aeration in my tank which did help tremendously but slowly went down, now its at 7.63, I tried opening the doors at night which didn't help very much. I have a co2 scrubber on the way but won't get here until mid-this week. The corals seem to find so far, not that closed, but not that open either. if I test my alk if I start dosing alk or kalk can I overdose causing calcium to go crazy?

To my understanding increasing, alk should increase pH, right? Even if I am not using Kalkwasser? Or is it the calcium buffering causing the pH to rise and has nothing to do with alk?

Any dosing you do needs to be measured. Dosing Kalk or any high-pH supplement needs to be added in a way that it doesn't swing your parameters much. My safe ranges are 0.2 for pH and 0.25 dKH during a single dose. Most don't worry about calcium as per @Randy Holmes-Farley said below 550 it's typically not a poblem.