Dosing question

[keithmeseroll]

My magnesium was at 1160ppm. I got fluval magnesium. It's a 30 gallon total water system. My question is how much to dose of the product. It's says Add 5 mL per 75 L (20 US Gal.) once a week. Weekly dosage provides 5 mg/L of magnesium. How much would I need to say raise my levels by 10ppm.thanks in advance

 

[GoVols]

My magnesium was at 1160ppm. I got fluval magnesium. It's a 30 gallon total water system. My question is how much to dose of the product. It's says Add 5 mL per 75 L (20 US Gal.) once a week. Weekly dosage provides 5 mg/L of magnesium. How much would I need to say raise my levels by 10ppm.thanks in advance

To your 30g just dose 4.5ml once a day until you reach your goal. You have to have some displacement, so your not really holding 30 gallons of water.

Do not exceed the daily limit to the product that you use or your ions could bind together making your big 3 (cal, alk and mag) to precipitate out causing lower big 3 parameters. Then it takes about 10 days before you are able to begin dose again.

Just be patient, at times it takes lots of daily doses until your mag truly levels out. Once your mag levels out, it should hold for quite some time, before the need to dose up mag again.

 

[Kmst80]

What are the KH and Calcium? Have you checked Salinity? If your salinity is low your magnesium will be low but so will be your Alkalinity and Calcium.

 

[GoVols]

What are the KH and Calcium? Have you checked Salinity? If your salinity is low your magnesium will be low but so will be your Alkalinity and Calcium.

yep,
A ture salinity level is very important when testing other parameters, before dosing.

Thanks so much for bringing that up.

 

[keithmeseroll]

What are the KH and Calcium? Have you checked Salinity? If your salinity is low your magnesium will be low but so will be your Alkalinity and Calcium.

Calcium 410
Kh floats around a 10ppm
Salinity 1.026

 

[Lavey29]

You may want to retest magnesium. If you are doing weekly water changes that suffices to replenish magnesium as it only depletes at 1/10th the rate of alk.

 

[keithmeseroll]

You may want to retest magnesium. If you are doing weekly water changes that suffices to replenish magnesium as it only depletes at 1/10th the rate of alk.

I test everyday and record it all down. Mag and calcium drop regularly but alk stays at about a 10. Actually have problems keeping those 2 up. Don't really know why. I use a red sea master test kit and red sea additives for all if needed. Alk stays the same but calcium will drop as well as magnesium. The only time my ALK will raise is if my calcium drops under 400. I use RO water too so not sure what's going on.

 

[Lavey29]

I test everyday and record it all down. Mag and calcium drop regularly but alk stays at about a 10. Actually have problems keeping those 2 up. Don't really know why. I use a red sea master test kit and red sea additives for all if needed. Alk stays the same but calcium will drop as well as magnesium. The only time my ALK will raise is if my calcium drops under 400. I use RO water too so not sure what's going on.

Depending on the age of the tank and how many corals, alk and cal typically drop proportionally with each other and at some point need to be dosed proportionally. I dose 35ml of alk in the day and 35ml of cal overnight. Magnesium only drops very slightly on a properly balanced tank and may need to be dosed weekly but typically water changes suffice.

 

[Kmst80]

I found my Mg went down very quick when the coralline took off and grew like crazy. Wouldn't explain the calcium though. I still dose Mg same amount as kh daily with weekly waterchanges.

 

[Lavey29]

I found my Mg went down very quick when the coralline took off and grew like crazy. Wouldn't explain the calcium though. I still dose Mg same amount as kh daily with weekly waterchanges.

You have an imbalance in your system. Mag should not be dropping or dosed equal to alk consumption

 

[GoVols]

I test everyday and record it all down. Mag and calcium drop regularly but alk stays at about a 10. Actually have problems keeping those 2 up. Don't really know why. I use a red sea master test kit and red sea additives for all if needed. Alk stays the same but calcium will drop as well as magnesium. The only time my ALK will raise is if my calcium drops under 400. I use RO water too so not sure what's going on.

You needed the Red Sea Pro kits.
But go with Salifert over their Pro mag kit.

Next time just grab Salifert cal, mag and alk kits.

 

[keithmeseroll]

You needed the Red Sea Pro kits.
But go with Salifert over their Pro mag kit.

Next time just grab Salifert cal, mag and alk kits.

I'll give them a try thanks

 

[Randy Holmes-Farley Verified Community Expert]

Most likely is test error somewhere (likely magnesium, but also possibly salinity). Remote possibility is a low mag salt mix manufacturing error.

Magnesium is not consumed more than about 1/10th of the rate of calcium, so to drop magnesium by more than 100 ppm would have required addition of more than 1,000 ppm of calcium. Consequently, i do not beleive that consumption is causing what you are observing unless you have been adding a lot of calcium for a long time with few water changes.

 

[keithmeseroll]

Got a refractometer and test it regularly. At an 0.0126. mag has been fluctuating a bit but remains at a steady decline. Currently at 1320 as of yesterday. Could it be that my tank is too new perhaps and leaching calcium and ALK out of some unseen source? My tank is about 6 months old at this point. Any thoughts would be appreciated

 

[Randy Holmes-Farley Verified Community Expert]

Got a refractometer and test it regularly. At an 0.0126. mag has been fluctuating a bit but remains at a steady decline. Currently at 1320 as of yesterday. Could it be that my tank is too new perhaps and leaching calcium and ALK out of some unseen source? My tank is about 6 months old at this point. Any thoughts would be appreciated

The most likely problem that is the answer for anyone reporting a magnesium rise or fall over a short period of time is test error or salinity changes. Trying to look for other explanations is generally a wasted effort. I've seen this movie hundreds of times.