High magnesium

[Maggie321]

I just got my red sea magnesium test kit and tested my tank. It reads it at 1760! I just did a wc 2 days ago. I thought those numbers were extremely high so I tested again and got the same. The photo is of my other parameters because that's easier than typing it out. Mostly acceptable except my phosphorus is high and I do not have an iodine kit to check that yet. I did not check ph, ammonia, or nitrites because the tank is not newly cycling and I don't see a need for it. The first column is what I understand as an acceptable level and the hand written column is what I tested last night. Should I do anything about the high magnesium?

 

[Smo]

Photo didn't appear to post. Mg is a bit high. What salt mix are you using? When you mix a fresh batch, prior to adding to your tank, how much Mg do your test results show?

 

[Maggie321]

Probably forgot to attach[emoji16]

 

[Maggie321]

Reef crystals. Tbh, I have never tested before putting it in my tank...never thought it would be a problem

 

[Smo]

Reef crystals. Tbh, I have never tested before putting it in my tank...never thought it would be a problem

Would help identify the source of high Mg. I assume you have not been dosing magnesium. So it has to be getting into your tank somehow.

 

[Maggie321]

Would help identify the source of high Mg. I assume you have not been dosing magnesium. So it has to be getting into your tank somehow.

Yes, but is there really anything that should/can be done about it? I assume it is coming in in the salt, but even if it is, the solution would be to switch salt, I don't want to do that, cause I just bought 2 more boxes... so, does anything Need to be done? Or is this my excuse to get more corals to have them consume it? I have Kalkwasser, but don't use it yet because my corals aren't consuming enough...

 

[Ubergroover]

test your source water. I test my tap water and my rodi water periodically just to see how my RO unit is working.

 

[Maggie321]

test your source water. I test my tap water and my rodi water periodically just to see how my RO unit is working.

That would not show up on a TDS meter? I have an inline and a handheld that I test the water with when I make a new batch of RODI. I didn't think the results would be accurate, considering the test kit is made for saltwater...does it work on fresh?

 

[andrew james]

Red sea's mg test kit stinks. It's way too easy to get a bad reading with it. I'm go get a Salifert and compare results

 

[Maggie321]

Red sea's mg test kit stinks. It's way too easy to get a bad reading with it. I'm go get a Salifert and compare results

dangit. I literally just got it Thursday.

 

[Smo]

Yes, but is there really anything that should/can be done about it? I assume it is coming in in the salt, but even if it is, the solution would be to switch salt, I don't want to do that, cause I just bought 2 more boxes... so, does anything Need to be done? Or is this my excuse to get more corals to have them consume it? I have Kalkwasser, but don't use it yet because my corals aren't consuming enough...

Could be a bad batch of salt that you might consider returning. Corals will consume very little of it. Only water changes with water having a lower Mg concentration will reduce it in your DT. If you aren't seeing any adverse effects--no immediate action required but I would be hesitant to add more corals until you get it below at least 1600.

 

[Smo]

dangit. I literally just got it Thursday.

I use the Red Sea Pro test kits and feel I get good results. Comparable to a LFS that tested my water independently with other test kits.

 

[Maggie321]

Could be a bad batch of salt that you might consider returning. Corals will consume very little of it. Only water changes with water have a lower Mg concentration will reduce it in your DT. If you aren't seeing any adverse effects--no immediate action required but I would be hesitant to add more corals until you get it below at least 1600.

Got it, I will be doing more testing soon. Will make a batch of RODI today and test both the water before, and the mixed water.
I wonder... If I get the salt mix for fish only, and everything tests low, can I use that to bring the magnesium down to acceptable levels then dose sodium bicarbonate and calcium to bring those numbers back up to proper amounts before addi g it to my tank? Or is that getting rediculous and risky?

 

[Smo]

Got it, I will be doing more testing soon. Will make a batch of RODI today and test both the water before, and the mixed water.
I wonder... If I get the salt mix for fish only, and everything tests low, can I use that to bring the magnesium down to acceptable levels then dose sodium bicarbonate and calcium to bring those numbers back up to proper amounts before addi g it to my tank? Or is that getting rediculous and risky?

Highly unlikely you have high Mg in your RODI water. Yes and good thinking to your follow-on questions.

 

[Maggie321]

Highly unlikely you have high Mg in your RODI water. Yes and good thinking to your follow-on questions.

So you're agreeing that it's too risky? I'm what I would consider inexperienced, although I think I have learned a lot, I would definately need a pro to coach me through this kind of thing.

 

[Smo]

So you're agreeing that it's too risky? I'm what I would consider inexperienced, although I think I have learned a lot, I would definately need a pro to coach me through this kind of thing.

No not at all. I would find a salt mix with low Mg and perform periodic water changes to reduce the DT Mg. Then dose alkalinity and Ca as required.

 

[Maggie321]

No not at all. I would find a salt mix with low Mg and perform periodic water changes to reduce the DT Mg. Then dose alkalinity and Ca as required.

Should I dose it to get it to acceptable levels before adding it to the tank? Or add it then check and dose the whole tank?

 

[Ubergroover]

That would not show up on a TDS meter? I have an inline and a handheld that I test the water with when I make a new batch of RODI. I didn't think the results would be accurate, considering the test kit is made for saltwater...does it work on fresh?

yes...but a TDS meter is only a estimate not a definitive reading. It will tell you the PPM of ionized solids. it wont tell you what it is. as far as I know SW test kits can be used for fresh, but not the other way around. The only reason I do it is because I used to get RODI water from a LFS and I was getting cyano. I did a PO4 check of the source water and found the reason. Now its just habit

 

[Maggie321]

And btw, my box says 1345 should be the magnesium level for my salinity... maybe I need the LFS to verify for me. The brand new test kit may be getting chucked... @andrew james

 

[Smo]

Should I dose it to get it to acceptable levels before adding it to the tank? Or add it then check and dose the whole tank?

Make changes slowly. If the new water has really low alkalinity and Ca, then you can dose to bring it up to optimum values.