Where is my alkalinity going?

texdoc77

New member
Hey gang I have a newish 150gallon that I have AWC 2 gallons a day with HW Marinemix (alk about 9.0). I have four fish, one zoa colony, one favite colony, one small/medium bubble coral and one LTA. My alkalinity has been slowly decreasing and when I checked it today it was 6.4. Does this sound right? I kinda thought water changes would be enough to keep the alk up for now, perhaps not. What is your experience?

Thanks in advance.

SC
 

Lowefx

New member
Did you use dry rock when you started the tank? Mine has also been doing the same thing, and the only thing I can think of is that the rock is soaking it in during the cycle. Just a guess.

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2una

New member
Between gfo/gfh & the aluminium PO4 absorber that phosguard your running i found the worst....I tried it for like 36 hours & pulled as it was just sucking out alk.
 

wrott

New member
Bacteria in sand bed will consume carbonate as a carbon source (like vinegar) especially if its still developing.
Try researching alk requirements between BB and sanded tanks.
 

texdoc77

New member
Actually not running any phosguard, I need to update that. I did use dry rock, not sure if that makes sense though. Might be something in the sandbed, guess I'll just dose for now. Anyone else have any thoughts for now?
 

Lowefx

New member
Seriously though, my alk has been dropping also with minimum corals in tank. I used dry rock and dry sand. I believe they absorb it very fast during the seating phase to build the bacteria needed. I might be crazy but that's what our tanks have in common.

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soulpatch

New member
I am in same boat Tex. I checked the HW salt and it mixed up to what we want but I am having to dose alk to my tank whereas my calc stays right between 420 and 440.

I need to get my calc reactor online so I no longer have to manually dose to keep things in line.

As others said I attribute it to the tank maturing and coraline and such soaking up the alk but I really have no idea.
 

Janetsplanet

New member
+1 here.

I started the aquarium with dry rock but "live" sand. It's seemingly impossible to keep the Alk up (was ~6.2dkh), but my ph (8.3), magnesium (1280) and calcium (500+) are in range, or even higher than I'd like.

Get this, my growth and coloration of all corals (LPS & SPS) are STUNNING!!! The best I've seen in my aquarium thus far. I didn't want to change whatever's happening in there, but also didn't want to risk a sudden turn around in inhabitants health. I researched to no avail, to answer the question. No answer, other than to raise Alk. I'm currently increasing it by adding baking soda to my ATO. It's working... slowly.

Very little visible coralline thus far, little spots here and there (mostly on plastic pieces) so it could be the coralline trying to get started.

If high calcium can lead to low Alk, then how do we fix it? I use Kent salt which tends to have higher calcium content than many.
 
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