Instant Ocean causing KH spike??

[alfredshouse]

Ive had a major tank crash and Im trying to diagnose what went wrong. Its been almost 12 hours now and Im looking at every possibility. I discovered my KH is off the chart. Even after a 1/3 water change and then a 50% water change both today. My KH is still off the chart. Makes me think the Instant Ocean is the culprit. Sure enough I test it and it is the problem. I know sounds stupid, I tested it again and again and I used my neighbours test kit and it reads the same thing. 140mg/l. Safe range is under 125mg/l.
Im pooped, but should I do another water change? What would be the point in that, if its the salt? If I get up in the morning and my corals are dead, "somebodies gonna get hurt real bad. Im not saying who, but I think you might know him." Sorry, I think the Robaxacet is kickin in.

[mark]

Might try mixing up a gallon and see what if comes up as.

I've recorded levels on a couple of different pails, tested alk on one 11.2, other 10.9.

[PoonTang]

what test kit are you using? is this a new bucket of salt? if not then i would suspect that it is ok.

[mark]

check this calculator, doesn't look like your alk is off compared to NSW

[Myka]

140 mg/l = 140 ppm = 7.84 dKH = 2.8 meq/l

This reading is not out of the normal range. I actually prefer my alk to be significantly higher at 9-10 dKH (160-178 ppm). Alkalinity is definately not your culprit. In my experience IO has varied very little from one bucket to another...sticking right around 11 dKH. I have had the alkalinity go up to 17 or 18 dKH in my tank, and the corals were just starting to show stress, but I didn't lose any.

If I were you I would be carefully doing a 50-75% water change as soon as I found out about the crash, and then proceed to do daily water changes of 30-50% until everything straightened out. Carefully, as in being sure to match temp and salinity very closely, and watching the critters for increased irritation.

[alfredshouse]

You guys are great, thank you for your help. I think my brains fried from all the stress. Im so glad the KH is okay.

[Myka]

What are your other readings the last time you took them before the crash? How long before the crash did you take them? What are they now?

Include as much as you can... temp, pH, salinity, ammonia, nitrite, nitrate, calcium, alkalinity, magnesium, phosphate...

What did you do to the tank in the 24 hours preceding the crash? Include everything, something as simple as stirring up the sand could be the cause.