Dosing your top off water

[jamesm]

Does anybody dose the top off water instead of having to dose the water in the tank daily? I have a five gallon bucket that automatically tops off the tank that I fill about every five days. Why couldn't I dose this water in the bucket to keep my Calcium, Alkalinity, and Magnesium in check?

 

[Lionfish Lair]

Your tank evaporates at variable rates. You could be dosing a little or a lot, depending on the day.

 

[Randy Holmes-Farley Verified Community Expert]

You could pick one of those, but not all three.

I dose limewater in my top off and it supplies all the calcium and alkalinity my tank needs.

 

[Rybren]

Your tank evaporates at variable rates. You could be dosing a little or a lot, depending on the day.

FWIW, I find that the evaporation rate on my setup is variable by season, but not so much on a daily basis. As a result, I really only have to adjust the amount of kalk and vinegar added to my ATO in the spring and again in the fall.

 

[miamiangler]

I just use Kalkwasser In my top off water .It has been keeping my KH at 9 , cal 450

 

[Lionfish Lair]

FWIW, I find that the evaporation rate on my setup is variable by season, but not so much on a daily basis. As a result, I really only have to adjust the amount of kalk and vinegar added to my ATO in the spring and again in the fall.

I guess take the phrase "about every 5 days", to be variable.

 

[stunreefer Verified Sponsor]

IME this can be done as mentioned above up until a certain point... if you're keeping large colonies of fast growing reef building stony corals (namely "SPS") many times "dosing" via ATO won't keep up with Ca/Alk demand. At that point dosing pumps or Ca reactor needs to be implemented.

 

[Lionfish Lair]

How tight is the recommended Mag range?

Lemme explain why I feel it's variable..... sometimes it's 5 gallons in 4 days, sometimes 5/5, sometimes 6 in 5. Albeit it doesn't sound like much, but think about it in terms of %. Sometimes it's 80%, sometimes it's right on at 100% and others at 120%. To me there's a big difference in 80 verses 120%. That's an 40% spread and I would be nervous about a 40% spread on Mg.

 

[aslmx]

You could pick one of those, but not all three.

I dose limewater in my top off and it supplies all the calcium and alkalinity my tank needs.

how do you mix your kalk Randy. Do you have a stir?

 

[Rybren]

Randy can correct me, but I believe that Mg is relatively stable over the short term - ie. 6 or 7 days. It may fluctuate a bit over the longer term, say a few months, but for the most part, water changes should take care of it.

If you are dosing kalk via the ATO, my understanding is that you don't want to add Mg to the ATO as well.

 

[Lionfish Lair]

Is there different preparations that influence availability? The reason I ask is, I remember dosing, testing (salifert) and logging, daily magnesium and calcium levels. That was maybe 8 years ago.

 

[mrcoffee2]

I add 2 scoops of Tropic Marin Bio Calcium to 5G of RODI water for my top off. This is what makes it so I never do a water change.

Also worth mentioning you may need a mag supplement.

 

[Randy Holmes-Farley Verified Community Expert]

I add 2 scoops of Tropic Marin Bio Calcium to 5G of RODI water for my top off. This is what makes it so I never do a water change.

Also worth mentioning you may need a mag supplement.

That is a poor idea. Tropic Marin Biocalcium will precipitate as calcium carbonate if mixed into fresh water.

It MUST be added dry to the aquarium.

 

[Randy Holmes-Farley Verified Community Expert]

Is there different preparations that influence availability? The reason I ask is, I remember dosing, testing (salifert) and logging, daily magnesium and calcium levels. That was maybe 8 years ago.

Once in the tank, all normal forms of calcium and magnesium have the same bioavailability.

Magnesium is very slow to deplete, if ever. 0.1 to 2 ppm per day, and that high end is only if calcium and alkalinity demand is very high.

 

[Randy Holmes-Farley Verified Community Expert]

how do you mix your kalk Randy. Do you have a stir?

I mix up 120 gallons in Brute cans and store it unstirred as I use it over several weeks.

 

[Randy Holmes-Farley Verified Community Expert]

Randy can correct me, but I believe that Mg is relatively stable over the short term - ie. 6 or 7 days. It may fluctuate a bit over the longer term, say a few months, but for the most part, water changes should take care of it.

If you are dosing kalk via the ATO, my understanding is that you don't want to add Mg to the ATO as well.

That's right, you cannot add magnesium into limewater. You'll precipitate magnesium hydroxide and deplete the alkalinity in it.

 

[Randy Holmes-Farley Verified Community Expert]

How tight is the recommended Mag range?

Lemme explain why I feel it's variable..... sometimes it's 5 gallons in 4 days, sometimes 5/5, sometimes 6 in 5. Albeit it doesn't sound like much, but think about it in terms of %. Sometimes it's 80%, sometimes it's right on at 100% and others at 120%. To me there's a big difference in 80 verses 120%. That's an 40% spread and I would be nervous about a 40% spread on Mg.

Magnesium must be added some other way and it is generally very stable.

FWIW, I've operated my tank this way for more than 19 years and it works fine for my tank.

I agree with others that it cannot meet all the needs of an SPS heavy tank.

 

[Lionfish Lair]

Are you saying you can or shouldn't add magnesium to a ATO water?

 

[mrcoffee2]

That is a poor idea. Tropic Marin Biocalcium will precipitate as calcium carbonate if mixed into fresh water.

It MUST be added dry to the aquarium.

I wont second guess you Randy! However, it does work wonderfully in my case.

 

[mrcoffee2]

Are you saying you can or shouldn't add magnesium to a ATO water?

Randy would know, but I would not add mag to ATO