Magnesium Ratio (2part) when using Kalkwasser AND 2 Part Recipe #2?

[jc-reef]

My limewater no longer keeps up with Alk/Ca demand and I have recently been supplementing my loss of Alk with 2 part Alk (baking soda disolved) & some Calcium Cloride in addition to the kalk.

I was wondering if I need to make an adjustment to my Mg ratio when I mix the 2 parts (Mg Chloride & Mg Sulfate) from ~7:1 Cups per gal I have been using for the past 2 years with my saturated limewater as my top off.....I read that when dosing ONLY 2 part for Alk/Ca that a Mg ratio (chloride:sulfate) of 5:3 is preffered vs Mg of ~7:1 when dosing only limewater. Since I am now dosing both methods for my Alk/Ca replacement, Do I need to adjust my Mg ratio via increasing the Mg Sulfate part????

I have figured that my Alk has finally stabilized in the 8.5-8.7 range (up from 5.8-6.1) when adding appox 1.5tsp of disolved baking soda (Alk) per day in a ~100g total system. I have also been dosing approx 15ml of Cal Chloride as well manually and my Cal level has been at 420. (This is on top of my saturated limewater drip for evap which is appox 1-1.5gal day).

Thanks!!
Jason

 

[bertoni]

If you're not doing many water changes, you probably should use a different ratio for the magnesium supplement. On the other hand, I did a 15% change once a month, and by my calculations, the ionic shift was very small, so I never bothered worrying with the magnesium supplement.

 

[wolfoholic]

Interesting same problem subscribing.

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[jc-reef]

I typically do 30% or so a month on a biweekly (sometimes weekly) basis. I'm curious if a ratio somewhere inbetween 7:1 and 5:3 would work? Any other chemistry guru's have an opinion on this?

 

[wolfoholic]

I kinda just figured out that two part supplements were the way to go vs dosing it all separate like I'd been doing. That's my problem in my tank. I killed my alkalinity but drove my calcium to 550! I makes sense if you think about it.

I'll read up more and start my own thread on this too since I don't want to jack yours and have a few different questions. Keep an eye open for it within the next few days!

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[wolfoholic]

I typically do 30% or so a month on a biweekly (sometimes weekly) basis. I'm curious if a ratio somewhere inbetween 7:1 and 5:3 would work? Any other chemistry guru's have an opinion on this?

Is there a way for you to measure it to get an idea where it's at? I was told having access is not a bad thing but having too little "ain't no good". Itok my water to my reef guy. Just had him do the test.

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[bertoni]

We can compute the exact ratio you would need in theory given the amount of Kalk per gallon, the evaporation rate per day, and the amount of the 2-part that you dose. Just as an example, if half the alkalinity comes from the Kalkwasser, then you should use half 7:1 and half 5:3 for the magnesium supplement.

 

[wolfoholic]

We can compute the exact ratio you would need in theory given the amount of Kalk per gallon, the evaporation rate per day, and the amount of the 2-part that you dose. Just as an example, if half the alkalinity comes from the Kalkwasser, then you should use half 7:1 and half 5:3 for the magnesium supplement.

I how do you know you aren't going off track at some point?

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[KCombs]

just chiming in with a less "Educated"/useful post

now that I'm saving money with the DIY 2part solutions, I don't mind the $20 for the ESV mag,,,,,

short answer: a 1gal jug is lasting me a lifetime; I don't measure my dosages of mag "per se" but pour a "glug" every 3-4 weeks ....
even with such unscientific dosing; my mag measurements have been absurdly stable

 

[bertoni]

I how do you know you aren't going off track at some point?

I'm not sure what you mean. If the tank is getting regular water changes, the ionic balance is going to be okay.

 

[jc-reef]

We can compute the exact ratio you would need in theory given the amount of Kalk per gallon, the evaporation rate per day, and the amount of the 2-part that you dose. Just as an example, if half the alkalinity comes from the Kalkwasser, then you should use half 7:1 and half 5:3 for the magnesium supplement.

I'm not sure what percent of alk replacement is coming from Kalk vs 2 part as I have always replaced my alk/cal via kalk until now that the kalk in no longer keeping up. I went ahead and mixed up 6.5 : 1.5 Mg since most likely the majority of alk/cal replacement still comes from Kalk instead of the 7:1 that I have always done in the past. I guess this should suffice for now and will see how it goes moving forward if I need to continue to increase my 2 part.

I wonder if anyone else adjusts the Mg ratio when dosing Kalk + 2 Part?

-----------

 

[bertoni]

I've never heard of anyone making a custom mix. I wouldn't bother. That said, if you measure the evaporation rate for a week or so, we could get a reasonable approximation of the Kalk consumption.

 

[jc-reef]

Its about 1.25 gallons a day...as it is on a timed doser. My 32g brute (28-30g finished product lasts just over 3 weeks). I have been dosing about 1.5tsp (disolved) per day of Alk (baking soda) and 15-20ml of cal (kent marine) per day and my Ca has been pretty stable so far at 420 and Alk now at 8.7-9.1. I will be switching my Ca to the BRS Cal which mixes down to about 1/2 the concentration as Kents (followed Randy's recipy of 1.25Cups dry Cal Chloride per gal finished product) so I will most likely be increasing my Ca dosing. I have been dosing my Ca by hand still as I am trying to hone in on avg daily usage.

 

[bertoni]

1.5 tsp and 1.25 g of saturated Kalk is about a 3:7 ratio, in terms of alkalinity provided. So if you made a mixture of 7 parts 7:1 to 3 parts of the 5:3, you'd match the two sources. A 5.4:1 ratio should be okay, magnesium chloride to magnesium sulfate.

 

[jc-reef]

thanks Jon!

 

[wolfoholic]

I'm not sure what you mean. If the tank is getting regular water changes, the ionic balance is going to be okay.

Right. Didn't think about the wc... ;-)

 

[bertoni]

You're welcome!

 

[lastduke]

Jonathan, how to convert the 2 part dosing back to kalk? is there a formula?

 

[wolfoholic]

Jonathan, how to convert the 2 part dosing back to kalk? is there a formula?

What do you mean convert back? Ml of two part to ml of Kalk?

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[bertoni]

One gallon of saturated Kalk is equivalent to about 60 ml of the recipe 1, if my memory is correct. That should be close enough. The higher pH of the limewater tends to change the consumption rate, anyway, so an exact conversion isn't useful.