alk and calcium issues

John Lohsr · Jun 5, 2017

I have a question. I have a 90 gal reef tank. its an upgrade from a 40 gal and has been setup for a month. The issue is I'm have trouble finding the sweet spot for alk and calcium.I use reef crytals salt. I manually dose ESV two part daily 25 mls I test with red sea alk, calcium and magnesium test kit. I'm dosing 25mls of 2 part. my tank is not heavily stock yet. mostly zoas, a acan, a favia. a digi and red monti cap. all small frags. The alk test 8.1, I test this daily.calcium tested this morning at 500, it was 450 two days ago. Mag test is high at 1500. I don't understand. If my mag is high, and the test kit is not wrong. why is my calcium so high and I cant get the alk to come up. I dosed only the alk part this morning and it came up after two hours but went back to8.1 after a few more hours. I have seen that if mag is low you cant get things to balance out. Any ideas?

nervousmonkey · Jun 5, 2017

First off, the Red Sea test kit is not accurate at all for magnesium. Try a different test kit or take some water to your LFS...
Second, since your tank is new, your alkalinity won't be stable with fluctuating nitrate levels. Quick increases in nitrate will cause alkalinity levels to decrease and vice versa.
Last, I am not sure why you are dosing? Especially for a tank that isn't heavily stocked and that doesn't have a lot of corals that consume alk and calc?? Not trying to be difficult and no need to answer the last question man. Just something to think about. I bet water changes will provide all the alk and calc you need, especially with Reef Crystals salt and the high alk levels that salt has.
Anyway, my recommendation is to:
1. Get a new test kit for magnesium. Salifert will work well.
2. Don't worry about alkalinity; just do water changes until you have corals that consume alkalinity.
3. Keep nitrate levels down.
Good luck!!

John Lohsr · Jun 6, 2017

nervousmonkey said:
First off, the Red Sea test kit is not accurate at all for magnesium. Try a different test kit or take some water to your LFS...
Second, since your tank is new, your alkalinity won't be stable with fluctuating nitrate levels. Quick increases in nitrate will cause alkalinity levels to decrease and vice versa.
Last, I am not sure why you are dosing? Especially for a tank that isn't heavily stocked and that doesn't have a lot of corals that consume alk and calc?? Not trying to be difficult and no need to answer the last question man. Just something to think about. I bet water changes will provide all the alk and calc you need, especially with Reef Crystals salt and the high alk levels that salt has.
Anyway, my recommendation is to:
1. Get a new test kit for magnesium. Salifert will work well.
2. Don't worry about alkalinity; just do water changes until you have corals that consume alkalinity.
3. Keep nitrate levels down.
Good luck!!

Thanks for the advice on my alk issues. I will try the salifert test kit. As for my tank being new everything in the 90s gal came from the 40 I upgraded from so I'm reality the only thing that's new is the glass. All the rock, the gravel, the sump is over a year old. I do 10% weekly water changes and my nitrates are low. Why I rise is I listened to the owner of the lfs where I bought my coral from, in home right I see he was making a sale. But I also dosed because of when I test alk is not between 9 and 12 dkh. I know that I'm just chasing numbers at this point, just one of many mistakes. I'll do a couple water Chang's and test like you advise. Thanks for all the help