Noob KH problem when altering MG and Ca

Gavin Noy

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Basically my KH is rising and its killing my acro and my tank looks fed up.

So i buy my saltwater from my LFS, its mixed at 1.026 salinity, 1300mg 350ca and 8kh. Im dosing into my salt water barrels enough MG granules (Reef advantage)
to get my mg to 1450 and seachem liquid calcium, 0.5ml /l to get my ca to 450. Mixed a full 25 liter drum to keep water changes consistent for water stability because i do a liter water change every other day in my 52l fluval evo.

My acro now has burnt tips and my kh has gone up to 12.5!!!!! Iv done a 10% water change with fresh pre mixed salt water with no calcium or mg dosed into it in an attempt to lower my kh, now i will do 2 liters every day until i get down below 10kh.

My question is, how do i get the mg and ca levels i need without blasting my kh through the roof? I have 2 test kits salifert kh mg and ca just to double check my readings.

My aim was stability thats why im pre mixing my mg and ca into the LFS water ready for little and often water changes but it has failed.

Looked at red sea salt and to hit good levels of mg and ca the kh will be 12kh regardless. Lost at the moment.

Thanks for any tips.
 

Randy Holmes-Farley

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Let's back up and I suggest you stop dosing immediately until we figure out what exactly you are using.

Seachem Reef Advantage Magnesium is OK for magnesium, although there is no reason to raise it further.

Seachem has multiple calcium products, none of which are called liquid calcium, and some would be a terrible choice.

Which product name or link exactly?

Reef Advantage calcium is a badly designed product, and will boost alk. Stop it immediately if that is what you are using.
 
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Gavin Noy

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Let's back up and I suggest you stop dosing immediately until we figure out what exactly you are using.

Seachem Reef Advantage Magnesium is OK for magnesium, although there is no reason to raise it further.

Seachem has multiple calcium products, none of which are called liquid calcium, and some would be a terrible choice.

Which product name or link exactly?

Reef Advantage calcium is a badly designed product, and will boost alk. Stop it immediately if that is what you are using.
Its seachem reef calcium liquid in a white bottle blue label. 50,000mg/l
 
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Gavin Noy

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IMG_1563.png
 

GARRIGA

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Let's back up and I suggest you stop dosing immediately until we figure out what exactly you are using.

Seachem Reef Advantage Magnesium is OK for magnesium, although there is no reason to raise it further.

Seachem has multiple calcium products, none of which are called liquid calcium, and some would be a terrible choice.

Which product name or link exactly?

Reef Advantage calcium is a badly designed product, and will boost alk. Stop it immediately if that is what you are using.
Randy,

Wouldn’t t it be safer to use sodium bisulfate to lower excess alkalinity vs WC? That’s what I do although I take the commercial route and use SeaChem acid buffer. Co2 seems dissipate rather quickly as my pH stabilizes shortly thereafter
 

Randy Holmes-Farley

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Randy,

Wouldn’t t it be safer to use sodium bisulfate to lower excess alkalinity vs WC? That’s what I do although I take the commercial route and use SeaChem acid buffer. Co2 seems dissipate rather quickly as my pH stabilizes shortly thereafter

That is a solution, but I'd first want to know the cause so it does not keep happening.
 

Randy Holmes-Farley

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Oh, sorry, I mistyped. That's the bad one lol Stop it and throw it away.

I'd avoid Seachem products in the future as they have a poor understanding of their own products.

I pointed out this problem to them int eh past, but they do nto seem to be interested in understanding.


"Reef Calcium™ is a concentrated (50,000 mg/L) bioavailable polygluconate complexed calcium intended to maintain calcium in the reef aquarium without altering pH. "

They seem to be ignoring the fact of what happens to the polygluconate. As it is metabolized, it adds alkalinity.

You may find your alk keeps rising as more and more of it is metabolized by bacteria, assuming it is not already done. It would add up to 2.8 dKH for every 20 ppm of calcium.
 

Randy Holmes-Farley

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Any product to lower alk lowers pH a lot. Often too much to use in your display.

My suggestion is to take new salt water, lower the alk very low (say, 1-2 dKH), aerate it to drive off excess CO2, and do water changes with it.

A good way is using sodium bisulfate:

 
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Gavin Noy

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Brill thank your for the rapid response. Down the drain it goes. The magnesium is ok though isnt it?
 

Randy Holmes-Farley

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Brill thank your for the rapid response. Down the drain it goes. The magnesium is ok though isnt it?

Yes, its fine, although I do not personally think it need to go higher than 1300 ppm, which about matches the ocean.
 
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