ALK too high?

[JMurphy97]

I'm mixing up a batch of salt for a water change and using IO. I was using reef crystals but I've decided to go back to regular IO and dose cal and mag to get to 1350 and 420 each.

When I first started my tank I used IO. I had no algae at all and that's without using gfo also. Since I switched to reef crystal I have this brown slime like algae.

Anyways the mag is testing at 1200, cal 295, and alk 12.3 at 35ppt in 2.5 gallons of change out water.

9.3 is what sk8r recommends on the new user section. Is 12.3 too high?

[SPS Tamer]

yea, i would say the alk is not quite ideal in comparison with the mag and cal.

[Duvallj]

http://www.advancedaquarist.com/2002/11/chemistry

I noticed your cal is low. Correcting it to around 420 might bounce the alk back down.


From what else your describing maybe you got a bad batch or it has settled out? I also use instant ocean but I haven't had cal mix up that low before.

[hilgert]

Have you tried tumbling the dry salt to counter the impacts of settling and ensure a homogeneous dry mix prior to mixing? Settling is not uncommon during transport.

[JMurphy97]

It was a new 50 gallon bag I bought yesterday. I shook it pretty vigorously before using. I added 2 part cal and mag to bring them up to 1450 mag and 420 cal but didn't retest the alk. From here I'll let the tank stabilize a few hours and retest everything.

Is high alk not common in IO?

[hilgert]

Here's a sticky on salt mixes at the top of this forum:

Synthetic Salt Mixes (http://www.reefcentral.com/forums/showthread.php?t=1714505)

Manufacturers change formulations from time to time, so this is likely not up-to-date. For example, I know that RSCP (Red Sea Coral Pro), which is what I use, has much higher Alk now than is listed in the sticky. But this should give you an idea of the ranges you should expect in general. Certainly the low Ca you initially measured would not be expected.

[tmz]

The recommended ranges for alk ,calcium and magensium are:

Alk 7 to 11 dkh;12 is borderline high imo.
Calcium 380 to 450ppm plus; 295 is very low.
Magnesium 1280 to 1350 plus ; 1200 is ok but could be higher.

[bertoni]

I agree that 12 dKH is borderline. I'd mix up the dry salt, as suggested, to see whether that helps, but 12 should be okay. If that's the only problem, I'd just reduce the supplementation for a bit to let the level drop if the tank itself gets that high.

Calcium at 295 ppm is unacceptable, though, and I'd get a second opinion from a different test kit. If the level is accurate, I'd consider returning the salt, although mixing up the dry salt might fix the problem.