Raises in Calcium, but no additive?

[nayrgaijin]

I've had this happen to myself before and didn't know why or how it happened, just did a waterchange with Instant Ocean and everything levelled out, but now it's happening to a friend of mine and were not sure how the Calcium just raises. He said he added Magnesium last week, but nothing else. What the heck is going on?
His is currently around 550. I've had mine jump from 440 to 500 one time.
Any ideas?

 

[BIG FISH]

I had this same thing happen to me but never did figure it out. Sorry I can't help I just wanted you to know you are not alone. Weird stuff huh.

 

[nayrgaijin]

Man, it so is!!!

Hopefully we have some chemist on here that knows why

 

[_Alex_]

just did a 7 gallon water change gonna check calcium again tomorrow and hope it is back down..... zoas and pali are not liking it at all.....

really frustrating when evreything was looking so good then in just a matter of days after not adding anymore mag the calcium goes shooting up..... went from like 440 to like 500+ in a matter of 3 or 4 days.

i have about 30 hermit crabs and coraline algae is going crazy so some of it has to be takin up somewhere i would think...

 

[RBursek]

testing kit errors, is you DKH dropping? If it is, you are using up CA, about 7ppm for every 1 drop in dkh, now if Mg is low it is hard to get and keep Ca up, so if you add Mg your Ca should stay up easier, but not increase on it's own, IO test at 1.0264 for Ca is suppose to be about 400 based on test at RC.

 

[_Alex_]

no dkh drops stays steady around 9-10 gonna test calcium again now and did water change on sunday...

 

[_Alex_]

dkh is at 9 cal still 500+ have water mixing with instant ocean was told its low in calcium?? i need to get my mag test back from ryan and check it but i thought if it was low calcium would be lower or swing???

planning to do another 5-10 gal water change either friday or sat so will see what happens after that

 

[Troylee]

I have read a few threads around like this and people are begining to think the rock is binding up calcium like it would po4 and after awhile leaching it back into the system.... Never did follow up on the thread but Anything is possible I guess....

 

[_Alex_]

i have not dosed calcium in probably 2 to 3 months? and put in some live rock i got from a loval club member that was downsizing tanks.....


it was holding good around 420 before the rock went in and been going higher and higher since.... so i guess it is possible

 

[skinz78]

I had Halimeda in my tank once and had a bunch die off and decompose some, I noticed my calcium raise at that time.

 

[RBursek]

I have read some place if chemicals get to out of balance, I think the high Mg will throw off an accurate Ca reading, by one of the other forums chem guros. there is some undisolved solids that disrupt the readiing. Test the mixed water change water before adding it for Alk, Ca and Mg. that will give you the accurate numbers of what you are adding, and that will give you an accurate number. And give you an idea of what is really your numbers.