Help me get ready for SPS - 3 Big problems.

Your logic is spot-on; however, total die-off of excess bacteria would not be immediate because as soon as it starts, the remaining live bacteria would begin feeding on it. The dying/feeding cycle would then wind down slowly until the population comes back to balance. Therefore, no ammonia spikes.

 

Ok big problems in little china.

Here are the readings for day 2.

Day 1 Day 2
Ca 350 300
Alk 9.8 9.0
Mg 1400 1200

This is two days after a 20% water change. Obviously there is some serious problems going on now. They are being used up at an alarming rate!. I have some Red Sea Ca and Alk solutions, should I dose this manually right now? Or wait till tomorrow to see what the readings are and make a decision after tomorrow?

Should I just order my dosing unit now?

Help help help.

 

That's a huge drop in Mag for consumption.

 

Which test kits are you using for testing? Have the test kits expired? Did you test a second time to confirm they were that low?

 

+1 Also, wild colonies almost always have some kind of pest in them (not that aquacultured never do but from reputable sources and your own dipping procedures you have better odds) so if you didn't dip them that could have been the prior SPS death sentence. Stable parameters are a big key to being successful in keeping SPS. Maricultered pieces are a bit easier then wild but still can be touchy.... but not horrible. Many of my pieces are Mari's, but frags from friends that have become more established to captive life are a bit easier and not so hard to keep for sure (although not necessarily EASY for a beginner either).

What do you have in the tank now that would be consuming so much? Definitely get the calcium up (slowly) over the next few days to 400 minimum (I run around 500). Personally I like Alk around 8 but Mg should be around 1350 although again I run mine a bit higher.

Also have you checked the levels of your new WC water, it may be depleted of what your tank needs before it even hits the tank.

 

Plus 1. I think it may be the water change water that dropped it so low. But in addition to that, Mag was high and may have been holding calc. down.

 

High magnesium helps calcium and alkalinity stay high...

 

Right, magnesium allows for calcium and carbonate to be elevated above levels that they otherwise wouldn't be able to be without their presence. Without it, both precipitate out rapidly. But that's not my point.

My point is that high magnesium typically causes the other 2 constituents to become unbalanced, which can just enhance the issue that we're seeing. That's why we test for magnesium. The first step that should be taken when correcting water chemistry is getting your magnesium value to the appropriate level. Once that is done, Alkalinity and calcium should fall in line.

Anyways, as I said, I think the issue is the water change water.

 

No, low magnesium prevents the balance. With low magnesium, high alk leads to low calcium... high calcium leads to low alk. High mag allows both to be high.

 

Right, higher magnesium keeps them from both precipitating out quickly; it acts almost as a buffer. However, it doesn't mean that they still can't become unbalanced through dosing. They can both be high and still be unbalanced, thus resulting in further issues.

Right now they are unbalanced. Lower magnesium first and raise calcium next.

But I digress. I'm not going to argue about this on this thread, it's not helping anyone.

I will point out a 3rd time, check you water change water.