Magnesium has a constant low reading of 1200 (both instant ocean and red sea) - help!

[danreef55]

I always have one of these handy. Only $9 and extremely accurate when you use a beaker

 

[Miemaes]

I am still blown away that an inventor of human pharmaceuticals still shows up for decades to answer the same "why is my pH low?" question. What a lesson in humility.

I think your issue is as simple as variances/calibration issues from inaccurate measurements lead to a lack of confidence in other measurements. I remember that stage. Invest in the right tools if youre going to invest in coral and invest into your understanding why the measurements matter and inter-dependencies for each of the things your measuring, most easily done with RHF literature.

You are absolutely right… I am definitely at that stage I’m trying to invest in all the proper tools (as much as my budget allows) Doing my tank maintenance today and applying all that I pick up from here. Will definitely go through more of his literature to get a better understanding of it all. Does adding calcium lower alkalinity btw? Now that I am able to get some questions… I’ve noticed that when I increase my calcium my alkalinity goes down and visa versa. How do I best raise and stabilize both? I’m dosing manually atm as I’m saving up for a dosing system. I feel my calcium gets used up faster then my alkalinity.

 

[Miemaes]

I would get or make some calibration fluid. May not be worth it to you but I recently added a TM precision hydrometer to verify my salt mix. I have refractometers and a Hanna salinity tester but they all need calibration. The Hydrometer doesn't lie as long as the temp is correct so I trust it 100 %.
Getting 35ppt out of 1/2c to 1 gal water seems off to me. I've been using reef crystals and regular IO for years and have never had 1/2c yield 35ppt. I mix 28 gallons at a time and have to use 16 cups of salt to get 1.025 (its how I prefer to measure) my math sucks but that's 32 half cups for 28 gallon of water. I would verify your refractometer is accurate.

Thanks. It stated that way on the bag of reef crystals. I assumed it was for the standard 35 ppt mix ratio. I went to look after reading your msg but it doesn’t really say… so you’re probably right it’s for a different gravity

 

[Miemaes]

I always have one of these handy. Only $9 and extremely accurate when you use a beaker

That is really cheap… I had just put in an order for one that costed around 33$ might order an extra one now at that price incase that one breaks

 

[Randy Holmes-Farley]

I always have one of these handy. Only $9 and extremely accurate when you use a beaker

How do you know it is accurate?

 

[ReeferZ1227]

You are absolutely right… I am definitely at that stage I’m trying to invest in all the proper tools (as much as my budget allows) Doing my tank maintenance today and applying all that I pick up from here. Will definitely go through more of his literature to get a better understanding of it all. Does adding calcium lower alkalinity btw? Now that I am able to get some questions… I’ve noticed that when I increase my calcium my alkalinity goes down and visa versa. How do I best raise and stabilize both? I’m dosing manually atm as I’m saving up for a dosing system. I feel my calcium gets used up faster then my alkalinity.

If your adding calcium within the appropriate range it should not be impacting alkalinity.

If youre unable to get a consistent salinity measurement, you wont be able to understand your tanks consumption, and whether or not your dosing because of a salinity swing or dosing because of consumption.

I use kalkwasser, its too dang simple and adds the right amount of Ca and Alkalinity so i dont have to add one or the other. There are circumstances where you will need to make minor corrections but until your alk consumption is > than evaporation you really dont have to do much with either other than make surr your alkalinity matches consumption, remains stable, and monitor Ca but likely not dose it. Plus the pH boost is a cherry on top.

Im assuming - your coral arent too happy nor mature and the only thing really consuming is coraline. Youre likely unnecessarily dosing as a result of compensating for salinity inconsistencies.

 

[ReeferZ1227]

I still strongly recomend you obtain a pinpoint salinity monitor. Price has increased so it is pricey, its electronic, has held calibration since i recieved it in march 2022. It adjusts for temperature, and is such a simple and consistent device i feel no reason to need to purchase any other salinity measuring tool, no guess work:

 

[danreef55]

In a wholesale facility we used multiple refractometers which were calibrated with a standard solution to establish a baseline with two hygrometers. The readings matched so we believed them to be accurate.
Randy you know far better than I so please educate us (as usual) Temperature is also critical

 

[Miemaes]

Make sure the pink tip is fully seated. If it not and its above the level of the liquid, you can pull air in from around the connection point. This was a huge problem with one of the Hanna

If your adding calcium within the appropriate range it should not be impacting alkalinity.

If youre unable to get a consistent salinity measurement, you wont be able to understand your tanks consumption, and whether or not your dosing because of a salinity swing or dosing because of consumption.

I use kalkwasser, its too dang simple and adds the right amount of Ca and Alkalinity so i dont have to add one or the other. There are circumstances where you will need to make minor corrections but until your alk consumption is > than evaporation you really dont have to do much with either other than make surr your alkalinity matches consumption, remains stable, and monitor Ca but likely not dose it. Plus the pH boost is a cherry on top.

Im assuming - your coral arent too happy nor mature and the only thing really consuming is coraline. Youre likely unnecessarily dosing as a result of compensating for salinity inconsistencies.

This makes sense. I need to get my calibration in check first. Already put in an order for calibration fluid and hydrometer. I need to look up Kalkwasser because that still feels like a very foreign topic to me But it sounds like a dream if you can use a single solution to handle your consumption rate for the most part. My corals are actually not too bad. The only one that is not happy is my hammer. It keeps making new heads but remains retracted. Here is a pic of my aquarium after my last water change

 

[Randy Holmes-Farley]

In a wholesale facility we used multiple refractometers which were calibrated with a standard solution to establish a baseline with two hygrometers. The readings matched so we believed them to be accurate.
Randy you know far better than I so please educate us (as usual)

I have no idea if yours or any others that folks would buy are accurate. Testing them against a standard is the best way to know.

 

[Randy Holmes-Farley]

Kalkwasser because that still feels like a very foreign topic to me But it sounds like a dream if you can use a single solution to handle your consumption rate for the most part.

Like any method, it has pros and cons. I like and used it for 20 years, but it's not perfect.

The Many Methods for Supplementing Calcium and Alkalinity - REEFEDITION

There is no aspect of reef aquarium chemistry more important than calcium and alkalinity. Many of my previous articles have described various aspects of these systems in detail. In reading those articles, aquarists will note one pervasive theme: that maintaining appropriate levels of each are...

www.reefedition.com

 

[Miemaes]

I still strongly recomend you obtain a pinpoint salinity monitor. Price has increased so it is pricey, its electronic, has held calibration since i recieved it in march 2022. It adjusts for temperature, and is such a simple and consistent device i feel no reason to need to purchase any other salinity measuring tool, no guess work:

What is $140 in this hobby right? You basically calibrate it with the fluid it comes with? How often?

 

[Miemaes]

Like any method, it has pros and cons. I like and used it for 20 years, but it's not perfect.

The Many Methods for Supplementing Calcium and Alkalinity - REEFEDITION

There is no aspect of reef aquarium chemistry more important than calcium and alkalinity. Many of my previous articles have described various aspects of these systems in detail. In reading those articles, aquarists will note one pervasive theme: that maintaining appropriate levels of each are...

www.reefedition.com

Thanks for sharing all these direct links. It’s going to be a study Sunday

 

[ReeferZ1227]

So my feedback above is all based on the assumption you have a salinity issue based on your magnesium discrepancies, further corroborated by you dosing calcium and based on the pictures you really shouldnt have to worry about mag or ca in that tank if youre doing consistent WC, maybe minor alk dosing. Alot of major assumptions, but nail down your salinity and then monitor everything else. Collect data, read, and go slow.

What is $140 in this hobby right? You basically calibrate it with the fluid it comes with? How often?

Exactly and it makes measuring your tank and meausring your WC salinity a breeze, and the subsequent corrections for salinity from creep and skimming.

I periodically check it, but i typically know how many grams of salt im adding to 10 gallons of water. So after mixing salt i check salinity. Any variances from expected results and ill check with calibration solution. Ive made 0 calibration adjustments since owning the device, i cant recall if it was actually calibrated out of box.

 

[Miemaes]

So my feedback above is all based on the assumption you have a salinity issue based on your magnesium discrepancies, further corroborated by you dosing calcium and based on the pictures you really shouldnt have to worry about mag or ca in that tank if youre doing consistent WC, maybe minor alk dosing. Alot of major assumptions, but nail down your salinity and then monitor everything else. Collect data, read, and go slow.


Exactly and it makes measuring your tank and meausring your WC salinity a breeze, and the subsequent corrections for salinity from creep and skimming.

I periodically check it, but i typically know how many grams of salt im adding to 10 gallons of water. So after mixing salt i check salinity. Any variances from expected results and ill check with calibration solution. Ive made 0 calibration adjustments since owning the device, i cant recall if it was actually calibrated out of box.

This really seems to simply things a LOT. Thanks so much for sharing that with me. I guess I know what to hint for for Valentines… Pinpoint hydrometer… lol

 

[ReeferZ1227]

This really seems to simply things a LOT. Thanks so much for sharing that with me. I guess I know what to hint for for Valentines… Pinpoint hydrometer… lol

Its a conductivity meter*. Theres plenty of reefers that are happy with refractometers and likely think im nuts suggesting a spend on the pinpoint. The rest likely use hydrometers, which are deadly consistent but extremely fragile. I view the pinpoint as a one and done, with longevity and ease of use as the justification, and the fact salinity must be accurate in order to keep the livestock happy and test for other key stuff.

Keeping to what i discovered works best for me - i saw conductivity meters* suggested by RHF in a thread so i bought it:

Real-time Salinity Monitor?

I was wondering if there was any Salinity testing equipment that actively reads Salinity in real-time, I use the Hanna Salinity Checker which I really enjoy but sometimes I get the feeling that it's not as accurate as a Refractometer.

www.reef2reef.com

 

[ReeferZ1227]

Oh, one last option - if youre going to go with a controller system (apex, etc) they typically have salinity monitors as well, so just another time sink you can obsess about, before you spend the money. I.e. do you just go with a full apex system for $xxx or spend $xxx on a bunch of different pieces that lack automation and communication (which may or may not be needed for your use case).

 

[legacy2mj]

I have Red Sea coral pro I just mixed yesterday so I read this and decided to test it. I mixed it to 1.025. The results are as follows (advertised/test) = Alk 11.5/11.5, Cal 450/450, mag 1350/1200

I have a calibrated refractometer and used salifert tests for all 3… as you can see Alk and cal matched up perfectly, but yes, Mag was substantially lower then what’s advertised… I don’t have a different type of mag test. Cause I’d love to cross check that result. Is it the salifert test? Or is the salt telling fibs? Hmmmmmm?
I dose all 3 independently to keep levels through the week and test every 2 days. So if the test is giving an accurate reading then I’m just supplementing the missing value in what I dose the tank. No biggy to me, but I could deff understand how this would be frustrating to some. Thanks for posting this, I wouldn’t have thought to look since my actual tank water always tests good.

 

[reef_ranch]

This makes sense. I need to get my calibration in check first. Already put in an order for calibration fluid and hydrometer. I need to look up Kalkwasser because that still feels like a very foreign topic to me But it sounds like a dream if you can use a single solution to handle your consumption rate for the most part. My corals are actually not too bad. The only one that is not happy is my hammer. It keeps making new heads but remains retracted. Here is a pic of my aquarium after my last water change

Your tank looks great. Don't change much if anything.

 

[ReeferZ1227]

Your tank looks great. Don't change much if anything.

This post isnt wrong.

I would still want to root cause measurement discrepancies, as OP is making potentially unnecessary dosing corrections, and may cause for it to not look great in the long run. If I was a betting man - that tank is not using more magnesium than is being replenished by WC.