Stabilizing Alkalinity & Calcium Levels - Help!

[samba_dad]

I must admit I am a little embarrassed asking this question, but I must be doing something terribly wrong with my 2-part dosing. I use Coral Pro Salt from Red Sea in my 65G tank. I am having an incredibly difficult time dialing in the correct 2-part dosage for my tank. Is there a method out there someone can point me to on how to arrive at the correct 2-part dosage amount so I can stop having massive Alk & Cal swings. My last 4 Alkalinity readings have been 9.2 (today), 10.6 (14 Dec), 14 (6 Dec), 8.8 (24 Nov). I keep trying to adjust my alkalinity dosing after each reading but just can't seem to get anywhere towards stable values. My last 4 Calcium readings have been 500 (today), 450 (14 Dec), 410 (6 Dec), 475 (24 Nov).

Should I always be using the same dosage for Ca and Alk for my 2-part? In other words, if I daily dose 48mL of Ca should I dose 48mL of Alk? I am using the Reef Foundation series of products for Ca, Alk & Mg. Some of my SPS seem to handle these swings just fine, other SPS RTN and die. My LPS seem to be doing well. I'm tired of killing SPS coral. Please help! Thanks for any help.

Red Sea Pro Test Kits
NH3 - 0 ppm
NO2 - 0 ppm
PO4 - 0.02 ppm
Ca - 500 ppm
Alk - 9.2 dKH
Mg - 1400 ppm
Salinity - 35 ppt
pH - 8.2
Temp - 76 deg

 

[Sabellafella]

I must admit I am a little embarrassed asking this question, but I must be doing something terribly wrong with my 2-part dosing. I use Coral Pro Salt from Red Sea in my 65G tank. I am having an incredibly difficult time dialing in the correct 2-part dosage for my tank. Is there a method out there someone can point me to on how to arrive at the correct 2-part dosage amount so I can stop having massive Alk & Cal swings. My last 4 Alkalinity readings have been 9.2 (today), 10.6 (14 Dec), 14 (6 Dec), 8.8 (24 Nov). I keep trying to adjust my alkalinity dosing after each reading but just can't seem to get anywhere towards stable values. My last 4 Calcium readings have been 500 (today), 450 (14 Dec), 410 (6 Dec), 475 (24 Nov).

Should I always be using the same dosage for Ca and Alk for my 2-part? In other words, if I daily dose 48mL of Ca should I dose 48mL of Alk? I am using the Reef Foundation series of products for Ca, Alk & Mg. Some of my SPS seem to handle these swings just fine, other SPS RTN and die. My LPS seem to be doing well. I'm tired of killing SPS coral. Please help! Thanks for any help.

Red Sea Pro Test Kits
NH3 - 0 ppm
NO2 - 0 ppm
PO4 - 0.02 ppm
Ca - 500 ppm
Alk - 9.2 dKH
Mg - 1400 ppm
Salinity - 35 ppt
pH - 8.2
Temp - 76 deg

I can sure help, i dont kno the direction for dosing with red sea, i would test rite now to see ur alk and calc, tomorrow at this same exact time test again and lets say your alk dropped 1.0 dkh, dose "equal and yes equal parts" alk and calc per intructions on the 2 part to reach 1.0 dkh

 

[Downbeach]

Are you doing any WC's between those readings? What is your SG, and what are you using to measure it with? If you're doing WC's and using an inaccurate/uncalibrated device for your SG, the amount of Ca, Mg and Alk you add will also vary with those WC's and make it very difficult to get the dosing of those elements tuned in. So, I would make sure of the accuracy of your SG first, use the same schedule and volume of water for your WC's, and go from there.

The uptake of Ca and Alk, by “stony” type coral, coralline algae, etc. in a reef system is ~20 ppm Ca to 50 ppm(2.8dKH) Alk(CaCO3), which is a ratio of 2 pts Ca to 5 pts Alk (2:5). Equal* doses of any two part supplements are designed to provide the same ratio's. So, they will all work but, I have found that the brand name products are going to be more expensive. I use the BRS (Randy’s recipe #1), so I buy both the Calcium Chloride and Soda Ash from BRS, although I have used A&H Baking Soda for the alk part as well.

Saturated kalkwasser also contains this same ratio, @ ~ 800 ppm Ca(2pts.) to 2,000 ppm CaCO3(5pts.). It also has the added benefit of utilizing some of the CO2 in your system, which may help keep your pH in line. Even though I'm using a two part recipe, I also still use the kalk in my dosing regimen. The problem with kalk, by itself, is that it’s limited in its ability to keep up with a high demand due to the fact that you’re limited to how much you can add to RO/DI water (2tsp.), and your evaporation rate. You can boost that to 3 tsp. with the addition of vinegar, but that also adds a carbon source, and potentially other issues.

I'd make sure the salinity is right, by measuring it using a properly calibrated (@35ppt/1.026) refractometer, or metering device. This will ensure you are adding enough Ca, Alk and Mg when you do your WC's. With normal WC's mixed to a salinity of 1.026, using a "reef" grade of salt mix, i.e. Reef Crystals, I've never had to add Mg.

*Depending on your load, your WC schedule and amount, it's also possible that because of the consumption rate(2:5) you may only have to dose the Alk part for a while, with the WC's keeping up with the Ca, in whole, or in part, along with your Mg.

 

[Randy Holmes-Farley Verified Community Expert]

Be careful of not overcorrecting, which is what causes up and down swings.

I would stick to using roughly the same dose, but for a variety of reasons (the recipe not exactly matching the demand in a given tank (we had a discussion of this today), different dosing pumps giving slightly different amounts, the two part actually made may not be exactly to recipe for mismeasurement reasons, etc.).

Let's get the alk stabilized first since it responds a lot faster to over or under dosing, and keep the calcium matched to it.

Then tweak the calcium as needed to keep it where you want it.

And, as noted, water changes may mess with the tank parameters if they do nto match the new salt water, so some correctiosn for that may be needed.

So today you are at 9.2 dKH.

What do you want the alkalinity to be?

 

[Randy Holmes-Farley Verified Community Expert]

Note that there may also be a lot of potential error in any given calcium measurement, so don't make changes based on every reading that shows a difference. Adjust slowly based on trends over multiple readings.

 

[Berlibee]

I'm dosing 2ml daily if I want it on the same level with my 20g tank and 2.5ml if I want it rise.

 

[samba_dad]

Be careful of not overcorrecting, which is what causes up and down swings.

I would stick to using roughly the same dose, but for a variety of reasons (the recipe not exactly matching the demand in a given tank (we had a discussion of this today), different dosing pumps giving slightly different amounts, the two part actually made may not be exactly to recipe for mismeasurement reasons, etc.).

Let's get the alk stabilized first since it responds a lot faster to over or under dosing, and keep the calcium matched to it.

Then tweak the calcium as needed to keep it where you want it.

And, as noted, water changes may mess with the tank parameters if they do nto match the new salt water, so some correctiosn for that may be needed.

So today you are at 9.2 dKH.

What do you want the alkalinity to be?

Thanks Randy for the response. I always value your input. I don't know if I have a specific alkalinity target number in mind - I just want my SPS happy - colorful and growing. According to the Red Sea Reef Care Program they suggest an alkalinity of 12.2 dKH for rapid growth of SPS frags. That is way high from most of what I read. Right now I have an LPS dominated tank (torch, hammer, frogspawn, leather, etc) with some soft mushrooms, polys & zoas that are all doing really well and growing. My tank is predominately frags with some of the LPS getting fist size. I have some SPS frags doing well also (setosa, psammacora). However, I am having acros turn brown then white and RTN most within 2 weeks of purchase. I have been working on getting my NO3 and PO4 up a bit and think I have been mostly successful there - without dosing the stump remover. I was running too clean with close to zero NO3 & PO4 levels according to my Red Sea Pro kits. I basically accomplished this rise by putting the skimmer on a timer and only letting it run I also have a PAR meter on order to ensure my spectrum is correct for my 2x XR15W Pro. Based upon those readings, I may augment with some T5 (blue+ and coral+) later. I am using 2x RW4 from Jebao and the wavemaker to get about 23X turnover per hour of circulation. So, I am hoping stabilizing Ca & Alk (and to a lesser degree NO3 & PO4) is going to be the turning point for my reef keeping experience with SPS.

I currently dose Ca from 10:30pm - 10:29am every 30 minutes (total of 24 doses per day). I dose Alk from 10:30am-10:29pm every 30 minutes (total of 24 doses per day). I use an Apex and BRS 1.1mL/min dosing pumps for everything. I do ~2 gal of water changes per day (broken up into 4 WC with the Apex). This amounts to about 17%/week of my total water volume.

I maintain salinity through the Apex conductivity probe which is calibrated monthly and checked against a calibrated refractometer weekly. My salinity remains almost perfectly constant at 35ppt.

I have a Triton test on order to ensure I don't have anything bad in the water. However, only 0-1 TDS RO/DI water has ever entered this tank. My maintenance is very consistent with weekly testing, skimmer cleaning, daily water changes for ~1 year. I do run Phosban and carbon reactors on a manifold setup with my main pump.

Don't know if this is related - I just got back from a vacation and noticed a bit of red slime algae in my tank. First appearance I have had of that. My Gyre had recently broken (again) and I switched to 2x Jebao RW-4. So, my flow has not been real consistent over last 1.5 weeks.

Questions
1) If I target something different than 12.2 dKH with my Coral Pro Salt I think it will cause more problems for me - right?
2) What is the next step to get the Alk stabilized?
3) I have tried waiting 4 days without supplementing to measure my drop in Alk & Ca per the Red Sea program. At the end of the 4 days, I averaged the results to obtain daily average. I measured 17.5ppm/day Ca, 0.8 dKH/day Alk, 10ppm/day Mg. The Mg number really had me scratching my head - that seemed high to me. Do these other numbers look reasonable to you? These are all Red Sea Pro test kits.

 

[samba_dad]

Are you doing any WC's between those readings? What is your SG, and what are you using to measure it with? If you're doing WC's and using an inaccurate/uncalibrated device for your SG, the amount of Ca, Mg and Alk you add will also vary with those WC's and make it very difficult to get the dosing of those elements tuned in. So, I would make sure of the accuracy of your SG first, use the same schedule and volume of water for your WC's, and go from there.

The uptake of Ca and Alk, by “stony” type coral, coralline algae, etc. in a reef system is ~20 ppm Ca to 50 ppm(2.8dKH) Alk(CaCO3), which is a ratio of 2 pts Ca to 5 pts Alk (2:5). Equal* doses of any two part supplements are designed to provide the same ratio's. So, they will all work but, I have found that the brand name products are going to be more expensive. I use the BRS (Randy’s recipe #1), so I buy both the Calcium Chloride and Soda Ash from BRS, although I have used A&H Baking Soda for the alk part as well.

Saturated kalkwasser also contains this same ratio, @ ~ 800 ppm Ca(2pts.) to 2,000 ppm CaCO3(5pts.). It also has the added benefit of utilizing some of the CO2 in your system, which may help keep your pH in line. Even though I'm using a two part recipe, I also still use the kalk in my dosing regimen. The problem with kalk, by itself, is that it’s limited in its ability to keep up with a high demand due to the fact that you’re limited to how much you can add to RO/DI water (2tsp.), and your evaporation rate. You can boost that to 3 tsp. with the addition of vinegar, but that also adds a carbon source, and potentially other issues.

I'd make sure the salinity is right, by measuring it using a properly calibrated (@35ppt/1.026) refractometer, or metering device. This will ensure you are adding enough Ca, Alk and Mg when you do your WC's. With normal WC's mixed to a salinity of 1.026, using a "reef" grade of salt mix, i.e. Reef Crystals, I've never had to add Mg.

*Depending on your load, your WC schedule and amount, it's also possible that because of the consumption rate(2:5) you may only have to dose the Alk part for a while, with the WC's keeping up with the Ca, in whole, or in part, along with your Mg.

Thanks Downbeach for the response. I certainly appreciate it. I don't use kalkwasser but have had used it in the past. I am doing small WC every 6 hrs for a total of 17% water volume per week. I use Coral Pro salt from Red Sea. My salinity is rock stable at 35ppt - maintained with Apex (calibrated monthly) and checked weekly with calibrated refractometer.

 

[samba_dad]

I can sure help, i dont kno the direction for dosing with red sea, i would test rite now to see ur alk and calc, tomorrow at this same exact time test again and lets say your alk dropped 1.0 dkh, dose "equal and yes equal parts" alk and calc per intructions on the 2 part to reach 1.0 dkh

Thanks Sabellafella for the response! I have stopped dosing for 4 days and taken an average reading. I get 17.5ppm/day Ca, 0.8dKH/day Alk and 10ppm/day Mg. How do these numbers compare to your tank? I dose every 30 mins with my Apex and the results I referenced were with the dosing matching these consumption rates. I am at a loss.

 

[tonkaoz]

I am having yhe same problem but all on the low side . I cannot get my alk up . Tops it has been is 7.6dkh and 133 on my hanna checker.

 

[twilliard]

Thanks Sabellafella for the response! I have stopped dosing for 4 days and taken an average reading. I get 17.5ppm/day Ca, 0.8dKH/day Alk and 10ppm/day Mg. How do these numbers compare to your tank? I dose every 30 mins with my Apex and the results I referenced were with the dosing matching these consumption rates. I am at a loss.

First, keep frustration down
Cant compare tank to tank. As Randy said work on your ALK
Test it daily and make SMALL adjustments to the the doser unit the desired number is stable.
Forget the math as it is confusing. If your alkalinity drops a little, add a little. No math needed to do that. If it goes up a little, dose a little less.
I am trying to make this to where you dont need a math Major to do this.

I am having yhe same problem but all on the low side . I cannot get my alk up . Tops it has been is 7.6dkh and 133 on my hanna checker.

Add more! Start increasing your dosing in small amounts daily till you hit your target.
If your adding 10ml one day add 12ml the next then 15ml and so on. It will go up.
When you do hit your target that would be your daily dosing amount
(Those ml numbers are just for example)

 

[Berlibee]

I maintain salinity through the Apex conductivity probe which is calibrated monthly and checked against a calibrated refractometer weekly. My salinity remains almost perfectly constant at 35ppt.
- and you're refractometer match the salinity probe readings?

 

[Randy Holmes-Farley Verified Community Expert]

Thanks Randy for the response. I always value your input. I don't know if I have a specific alkalinity target number in mind - I just want my SPS happy - colorful and growing. According to the Red Sea Reef Care Program they suggest an alkalinity of 12.2 dKH for rapid growth of SPS frags. That is way high from most of what I read. Right now I have an LPS dominated tank (torch, hammer, frogspawn, leather, etc) with some soft mushrooms, polys & zoas that are all doing really well and growing. My tank is predominately frags with some of the LPS getting fist size. I have some SPS frags doing well also (setosa, psammacora). However, I am having acros turn brown then white and RTN most within 2 weeks of purchase. I have been working on getting my NO3 and PO4 up a bit and think I have been mostly successful there - without dosing the stump remover. I was running too clean with close to zero NO3 & PO4 levels according to my Red Sea Pro kits. I basically accomplished this rise by putting the skimmer on a timer and only letting it run I also have a PAR meter on order to ensure my spectrum is correct for my 2x XR15W Pro. Based upon those readings, I may augment with some T5 (blue+ and coral+) later. I am using 2x RW4 from Jebao and the wavemaker to get about 23X turnover per hour of circulation. So, I am hoping stabilizing Ca & Alk (and to a lesser degree NO3 & PO4) is going to be the turning point for my reef keeping experience with SPS.

I currently dose Ca from 10:30pm - 10:29am every 30 minutes (total of 24 doses per day). I dose Alk from 10:30am-10:29pm every 30 minutes (total of 24 doses per day). I use an Apex and BRS 1.1mL/min dosing pumps for everything. I do ~2 gal of water changes per day (broken up into 4 WC with the Apex). This amounts to about 17%/week of my total water volume.

I maintain salinity through the Apex conductivity probe which is calibrated monthly and checked against a calibrated refractometer weekly. My salinity remains almost perfectly constant at 35ppt.

I have a Triton test on order to ensure I don't have anything bad in the water. However, only 0-1 TDS RO/DI water has ever entered this tank. My maintenance is very consistent with weekly testing, skimmer cleaning, daily water changes for ~1 year. I do run Phosban and carbon reactors on a manifold setup with my main pump.

Don't know if this is related - I just got back from a vacation and noticed a bit of red slime algae in my tank. First appearance I have had of that. My Gyre had recently broken (again) and I switched to 2x Jebao RW-4. So, my flow has not been real consistent over last 1.5 weeks.

Questions
1) If I target something different than 12.2 dKH with my Coral Pro Salt I think it will cause more problems for me - right?
2) What is the next step to get the Alk stabilized?
3) I have tried waiting 4 days without supplementing to measure my drop in Alk & Ca per the Red Sea program. At the end of the 4 days, I averaged the results to obtain daily average. I measured 17.5ppm/day Ca, 0.8 dKH/day Alk, 10ppm/day Mg. The Mg number really had me scratching my head - that seemed high to me. Do these other numbers look reasonable to you? These are all Red Sea Pro test kits.

I generally recommend 7-11 dKH. While 12 dKH will make many hard corals grow faster, it also increases abiotic precipitation of calcium carbonate on pumps and heaters, and it risks burnt tips on SPS in tanks with very low nutrients. Perhaps a lower alkalinity and/or more nutrients will be helpful in your case.

IMO, where you are now at 9 dKH is fine.

The tank need not match the salt mix, but if you do big water changes (as opposed to more smaller ones), then you may need to take that into account in terms of alkalinity dosing on those days.

How big of water changes do you do?

i'd just keep the alk dosing where it is, match calcium to it, and see what alk does over the next several days.

 

[Randy Holmes-Farley Verified Community Expert]

I am having yhe same problem but all on the low side . I cannot get my alk up . Tops it has been is 7.6dkh and 133 on my hanna checker.

How much of what are you dosing, and what happens if you dose more?

 

[Randy Holmes-Farley Verified Community Expert]

Thanks Sabellafella for the response! I have stopped dosing for 4 days and taken an average reading. I get 17.5ppm/day Ca, 0.8dKH/day Alk and 10ppm/day Mg. How do these numbers compare to your tank? I dose every 30 mins with my Apex and the results I referenced were with the dosing matching these consumption rates. I am at a loss.

Most people dose about 1-4 dKH per day, some more. 0.8 dKH per day is not particularly unusual.

 

[bobbyM]

I maintain salinity through the Apex conductivity probe which is calibrated monthly and checked against a calibrated refractometer weekly. My salinity remains almost perfectly constant at 35ppt.
- and you're refractometer match the salinity probe readings?

*Your

 

[tonkaoz]

First, keep frustration down
Cant compare tank to tank. As Randy said work on your ALK
Test it daily and make SMALL adjustments to the the doser unit the desired number is stable.
Forget the math as it is confusing. If your alkalinity drops a little, add a little. No math needed to do that. If it goes up a little, dose a little less.
I am trying to make this to where you dont need a math Major to do this.


Add more! Start increasing your dosing in small amounts daily till you hit your target.
If your adding 10ml one day add 12ml the next then 15ml and so on. It will go up.
When you do hit your target that would be your daily dosing amount
(Those ml numbers are just for example)

i feel like im dosing to much . i dose 120 ml a day . but i do have a 220 with a 75 gallon refuge and a 30 gallon sump . and that still isnt enough . ive been checking it every day and it slowly drops . i checked 2 days ago and my alk was 116 on my hanna checker . should i dose more ?

 

[tonkaoz]

How much of what are you dosing, and what happens if you dose more?

im dosing 120ml a day on my ghl doser . i have a 220 dt 75 refuge and a 30 sump . i feel like thats alot but maybe im wrong. my last test was 2 days ago and it was 116 on my hanna checker . ill post the last 4 times i checked and all my levels when i get home . but thank you for your help

 

[twilliard]

Yes dose more and as Randy said what are you using?
As in what 2 part are you using

 

[Randy Holmes-Farley Verified Community Expert]

im dosing 120ml a day on my ghl doser . i have a 220 dt 75 refuge and a 30 sump . i feel like thats alot but maybe im wrong. my last test was 2 days ago and it was 116 on my hanna checker . ill post the last 4 times i checked and all my levels when i get home . but thank you for your help

Assuming this is my DIY two part, like BRS sells, then 120 ml per day in 300 gallons of total water is only 0.55 dKH per day.

That is not very much at all.

Even coralline algae alone in a soft coral tank can consume 2 or more dKH per day.

So dose more if you want the alkalinity higher.