Alkalinity Question

[denverjon]

I've been having issues for much of the last 18 months and haven't been able to pinpoint the problem. I've lost quite a few sps and even a few lps and softies. I decided to get an ICP analysis done that tests some 20 different things and there were no major red flags. My potassium and strontium were low, but I wouldn't expect that to be the root of my problems. When talking to the store owner who did the test, he started asking questions about my alkalinity. I dose two part and my alk usually tests at around 8.8 - 9 once I'm done dosing, but I'm only dosing once a day, so I'm wondering if the issue might be that my alk is dropping too much between dosing? He suggested that I spread out the dosing to several times over a 24 hour period to make it more stable. Do you agree and could that be the root of my problems? All of my other parameters are good...Calcium is 425, Magnesium is 1275, Phosphate is .08, Nitrate is 2 , Salinity is 1.026. I appreciate the advice!

 

[denverjon]

bump

 

[BlueCursor]

Stability is key for LPS, even more so for SPS.
​

How many ml of alk do you dose a day? If it's a few ml, then it probably isn't an issue (you didn't state your tank size either). If you dose 62 ml a day into a 100 gal tank like I do, dosing that all at once is a disaster. Also, what size is your tank?

You haven't said how they die. Are they slowly wasting away, RTN, STN? These are caused by different problems. When I started I couldn't keep LPS alive to save my life. Turns out my lights were nowhere close to being as bright as I thought they were. Once I borrowed a PAR meter and upped my lights, things stopped dying and started growing.

As far as dosing, if you can't get an automatic doser, then definitely break it out into multiple times a day. You can easily dose morning, after work, and before bed. That breaks it out to 3 times a day instead of 1. The other thing to consider is when you test in relation to when you dose. If you have a dosing machine, when you test isn't critical. If you are manually dosing, your reading is going to be harder to nail down. Test before you dose.

 

[Cory]

Tell us more about your system. Flow, lighting. Can you post the icp results here?

 

[denverjon]

I'm not sure how to post the results without it being a really long post but all the parameters were great except potassium and strontium. No heavy metals, no obvious toxins, etc. I don't believe my flows and lighting are the issue...I run 3 MP40's and my lighting is a combo of 250W MH's, T5's and LED's. At this point, I'm trying to eliminate all potential issues and I keep coming back to alkalinity. Even though it tests at 8.8 - 9 after dosing, I'm starting to think that the instability caused by my dosing just once a day might be the issue.

 

[PatW]

I have read that you do not want to change ALK by more than 1 DKH unit at a time by dosing. If you are only adding enough to move the needle by a half DKH or less, I would think you would be fine. If you are at more than a DKH, you might think of getting a controller and a doser and adding several small doses per day to maintain DKH levels.

 

[Cory]

Stability is key for LPS, even more so for SPS.
​

How many ml of alk do you dose a day? If it's a few ml, then it probably isn't an issue (you didn't state your tank size either). If you dose 62 ml a day into a 100 gal tank like I do, dosing that all at once is a disaster. Also, what size is your tank?

You haven't said how they die. Are they slowly wasting away, RTN, STN? These are caused by different problems. When I started I couldn't keep LPS alive to save my life. Turns out my lights were nowhere close to being as bright as I thought they were. Once I borrowed a PAR meter and upped my lights, things stopped dying and started growing.

As far as dosing, if you can't get an automatic doser, then definitely break it out into multiple times a day. You can easily dose morning, after work, and before bed. That breaks it out to 3 times a day instead of 1. The other thing to consider is when you test in relation to when you dose. If you have a dosing machine, when you test isn't critical. If you are manually dosing, your reading is going to be harder to nail down. Test before you dose.

Curious what lights you used and what you changed to? What were the par readings?

 

[Cory]

I'm not sure how to post the results without it being a really long post but all the parameters were great except potassium and strontium. No heavy metals, no obvious toxins, etc. I don't believe my flows and lighting are the issue...I run 3 MP40's and my lighting is a combo of 250W MH's, T5's and LED's. At this point, I'm trying to eliminate all potential issues and I keep coming back to alkalinity. Even though it tests at 8.8 - 9 after dosing, I'm starting to think that the instability caused by my dosing just once a day might be the issue.

Have you made an alkalinity standard? Icp doesn' test for it.

 

[Cory]

Also potassium can cause color loss if it' low.

 

[denverjon]

Thanks for the advice. My tank is 210 gallons (260 total with the sump). I've got two 250w MH pendants along with two sets of Reefbrite T5 Led Hybrids. Ive got plenty of lighting so I don't think that's the issue.

I'm dosing around 75 ml a day over the course of a couple hours using a BRS dosing pump, so I would be willing to bet that's what's causing the issue. I have had a few issues with lps but the majority of my problems are with sps. Some will rtn starting at the base and others will completely rtn in a matter of hours.

 

[Cory]

Thanks for the advice. My tank is 210 gallons (260 total with the sump). I've got two 250w MH pendants along with two sets of Reefbrite T5 Led Hybrids. Ive got plenty of lighting so I don't think that's the issue.

I'm dosing around 75 ml a day over the course of a couple hours using a BRS dosing pump, so I would be willing to bet that's what's causing the issue. I have had a few issues with lps but the majority of my problems are with sps. Some will rtn starting at the base and others will completely rtn in a matter of hours.

Iirc stn from the base up could be low potassium

 

[cilyjr]

Iirc stn from the base up could be low potassium

This would surprise me. I'd like to see some studies pointing to this.

To the op,
When you are dosing alk are you using soda ash or bicarbonate? What is your ph swing ?

 

[Randy Holmes-Farley Verified Community Expert]

I dose two part and my alk usually tests at around 8.8 - 9 once I'm done dosing, but I'm only dosing once a day, so I'm wondering if the issue might be that my alk is dropping too much between dosing?

How much alk (in dKH) are you dosing each day?

Knowing this is the only way to know if there's any substantial alk swing

 

[denverjon]

Randy - In answer to your question, I'm dosing 140 ml a day, which raises the alk from 8 to 8.8.

 

[Flippers4pups]

Are you dipping your corals? And what softies are/were keeping and what happened when they died? Did the SPS decline at the same time as the softies?

 

[denverjon]

The way I wrote the original post made it sound like I've lost more softies than I actually have. I've only lost one, a green toadstool, and the sps issues started well before then.

 

[BigJohnny]

Also potassium can cause color loss if it' low.

And stn/rtn in my experience, if really low.

 

[Flippers4pups]

@denverjon, Are you dosing alkalinity in powdered form or in solution? And are you adding it to the DT or in sump?

 

[Randy Holmes-Farley Verified Community Expert]

I don’t think that alk variation from 8 to 8.8 dKH each day is going to cause loss of SPS, but splitting it into 2 or more doses a day will provide a more stable alk to them that is probably desirable. [emoji3]

 

[Ivan Stoiljkovic]

Measure PAR, too much light will kill them in a few days, too little light will kill a lot slower (maybe a month).
I think par meter is a MUST with sps.
As far as lps I think too much flow/light, leaning towards the light.

But other experts will weigh in. Just my modest opinion