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Magnesium is always low but cal alk is high


Candymancan

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Im trying to figure out my moms 30g reef i made for her.  Itd been running a year along side my 135g.  Same sand. Same rock. Same corals in fact frags are from my tank.  Ligjts are  the same T5s cept 4 it has 2.  

 

Fish are all fine, corals are fine.  It has a kenya tree a frag from my green slimer acro, bout 5 frags of my purple and red.orange plating monti and it also has a purple cespitulara.   Oh and a 4 headed octospawn.  

 

All the other frags are bout the size of maybe two fingers.  So nothing huge.  They are growing and growing fairly well.  Not as fast as in my 135 but still growing nontheless.

 

I havent had the chance to maintain the tank for 3 months because my brother his wife and kid moved in for awhile and took over my moms room temp while she had the smaller guest room ( just made sense for 3 ppl to take the lsrger room vs a tiny bedroom) and ive been trying to stay out and resoect their privacy so i never had much chance to maintain it.

 

I did one water change in 3 months. My brother overfed the fish too.. they are gone and i checked the water params.. nitrates were 80ppm.  Calcium was 420 alk was 13.  Magnesium was 1050.  No fish or corals deaths not even the acropora lol in fact they all grew fine lol.

 

I did a 60% water change last night.  Nearly 20 gallons of water.  3 1.2 5 gal buckets worth.  And i checked the params today.  Alk is 13 calcium is 440.. magnesium is still low though at 1150.  I figured after 20 gallons of reef crystals itd go up more then it did from 1050.  

 

My tank its 1290 and i plan to do a water change soon to bring it back to 1350.  

 

I guess i have to do another water change in that tank. Ill probably do another 50% or more.  I want the mag at 1300 at least.  And i know reef cryatals is at 1350 all the time for me anyway.

 

My question is how was magnesium so low to begin with at 1000 basically yet alk was 13 and calcium was 420..  That really confuses me because in my 135 i lose 1 point of alk a day and i have to keep dosing daily.. calcium drops fairly fast too and mag drops much slower so i usually only have to do a water change once a month to get the mag back up.  (Its cheaper doing water changes with salt then buying magnesium and dosing trust me i tried brs mag overpriced junk)

 

Sorry for a long post but yea.  The way mag works its the slowest of the 3 outa mag alk and calc to drop.. yet the tank had low mag and high alk and calcium.. makes no sense.

 

I also just added today a probly 20 head chunk of a teal color trumpet and a fist sized chunk of purple cespitulara since my colonies are huge of those in my 135.. so i am trying to get water params the same as my tank so i dont kill the new corals

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I had the very issue when I used reefcrystals. Not everyone does. Its hit and miss.

 

 

My ca was always 440 -460

Alk was around 7- 9(sw didn't mix consistently)

Mag 1100-1150

 

Mag was always low. I had to dose through the week to get it to 1200 then waterchanges would drop it.

 

The only way around it was testing the mag in my newly mixed sw, dosing to raise it before waterchanges.

 

I no longer do this, it's more costly then using a different salt.

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  • 4 weeks later...
On 12/11/2019 at 1:28 PM, Candymancan said:

Magnesium was 1050.

I don't know of a minimum or maximum level for calcium or magnesium where the level starts to be a problem -- doesn't seem to be a problem in either case. 

 

1050 is really low though.

 

A) What is your specific gravity or salinity?

B) Make sure your test kit is not expired

C) Consider dosing something to replace the magnesium that's missing instead of doing water changes.

 

If you find that your salt is mixing low on magnesium, consider using smaller packages of salt that you can use all at once. (the best option and how the salt is really intended to be used)

 

If you have a really small tank that you do really small water changes on, you would consider buying really small packages of salt....like the 10 gallon size from Instant Ocean.

 

If you have a large tank, then consider making your saltwater in a 50-60 gallon vessel so you can use a whole 50 gallon bag of salt at once.

 

OR take care to re-mix the salt before using it.  E.g. roll a bucket of salt around on the floor for a while before using.

 

I'm sure you get it.  👍

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4 hours ago, mcarroll said:

I don't know of a minimum or maximum level for calcium or magnesium where the level starts to be a problem -- doesn't seem to be a problem in either case. 

 

1050 is really low though.

 

A) What is your specific gravity or salinity?

B) Make sure your test kit is not expired

C) Consider dosing something to replace the magnesium that's missing instead of doing water changes.

 

If you find that your salt is mixing low on magnesium, consider using smaller packages of salt that you can use all at once. (the best option and how the salt is really intended to be used)

 

If you have a really small tank that you do really small water changes on, you would consider buying really small packages of salt....like the 10 gallon size from Instant Ocean.

 

If you have a large tank, then consider making your saltwater in a 50-60 gallon vessel so you can use a whole 50 gallon bag of salt at once.

 

OR take care to re-mix the salt before using it.  E.g. roll a bucket of salt around on the floor for a while before using.

 

I'm sure you get it.  👍

Low magnesium can cause alk and ca imbalance. Mag should be 1280.

 

 

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I meant that I am not aware of any physiological issues with the animals that relate to either low or high magnesium, or low or high calcium. 👍

 

Both elements seem to be available in humongous amounts, and there is no apparent "too much ".

 

Contrast that with alkalinity where too much is dangerous AND too little is dangerous.

 

Calcium and magnesium are not like that.

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1 hour ago, mcarroll said:

I meant that I am not aware of any physiological issues with the animals that relate to either low or high magnesium, or low or high calcium. 👍

 

Both elements seem to be available in humongous amounts, and there is no apparent "too much ".

 

Contrast that with alkalinity where too much is dangerous AND too little is dangerous.

 

Calcium and magnesium are not like that.

I have read that high mag isn't an issue. I myself used to have it between 1500-1600, there were no ill effects.

 

 

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At various times I've had Mg around 1000 and over 1500+.  I think I computed a Ca overdose I did one time to be around 900 ppm.  No problems under any of those circumstances. 

 

(Well, I was having a problem getting the doser dialed in....no problems with the animals in the tank tho!! 😆)

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26 minutes ago, mcarroll said:

At various times I've had Mg around 1000 and over 1500+.  I think I computed a Ca overdose I did one time to be around 900 ppm.  No problems under any of those circumstances. 

 

(Well, I was having a problem getting the doser dialed in....no problems with the animals in the tank tho!! 😆)

Ya, I've never had issues when ca or mag were high.

 

 

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Sorry again... wrong thread. Way too many tabs open. It's been a while since on the forums.

 

I will be mixing whole batches of salt at a time from now on. Now to find a reasonably priced salt mixing/storage container (food grade right?) because I do not want to be purchasing small batches all the time. If anyone has a good place I can find a 50-60g container, I am all ears.

Thx

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Cheapest is to find a used pickel or olive barrel, or similar.  LOTS of used food-grade barrels out there, those are just my favorite because of the screw-top lid....look on craigslist and even ebay.

 

Brute trashcans are all FDA approved and aren't too expensive, but I think the biggest is 44 gallons...

 

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