Alkalinity >14 dKH ???? What, if anything, should do?

[scubaman99]

Hello,

This is my first post so please forgive me if I "mess something up":

I have a 175 gallon (+20 gallon refugium) mixed reef tank (LPS, softies, fish). Below are my current tank parameters

Alkalinity - >14dKH (Red Sea Test Kit)
pH - Fluctuates between 8.0-8.1 (lower at night; American pinpoint monitor)
Calcium - 470 ppm (Red Sea Test Kit)
Specific Gravity 1.022 (working on raising it slightly)
Magnesium - 1220 (Red Sea Test Kit)
Nitrate - <10 ppm (Red Sea Test Kit)
Phosphate - 1 ppm (Red Sea and Salifert) - I know this is too high and I just added GFO to my reactor. Ran Phosguard for a few weeks and didn't seem to work.

Questions
1. My alkalinity is off the charts but everything seems to be doing okay and my calcium levels are acceptable, do I mess with it? I stopped dosing 2 little fishies A+B for the time being to see if it would go down on its own. I also stopped dosing Kent superbuffer dkH (dont think I need this and the 2-part anyway?). I did read that the Kent superbuffer does contain borate which could be throwing of my alkalinity results if it got high enough.

2. Any reason why phosguard wouldn't work? Hopefully GFO in a reactor does the trick. At least my clean up crew is well fed with algae on the glass.

Thanks,
Todd

 

[CodyRVA]

Welcome to R2R!

1. I agree, i don't think you need the buffer and 2 part. I would use 2 part, but that's my preference. I would confirm your readings with other test kits, maybe go to a LFS. Start there and confirm your ALK before doing anything. If you confirm it's that high, I would slowly bring it down. It's quite high so you may still have to dose, just dose less and less vs just letting it bottom out on its own. 14 dKH is high, but you'll do more harm if you just drop it down to 10 in an hour vs letting it drop over over time.

2. It might not be the phosguard, but the source of your PO4 is still active and clearly strong. I had a PO4 spike and had to run GFO for a while before it really came down and stayed there. Find the source of the nutrients and resolve it, use the GFO to correct the situation by bringing it down. Don't rely on GFO/phosguard on a daily basis or you'll likely run into trouble.

I would also try and raise your MG a bit, but not a huge deal right now.

 

[Randy Holmes-Farley]

I'd try to get an actual alk reading. Use as many syringes of titrant as needed to get an actual measurement.

Stop the superbuffer and two part.

Once the alkalinity drops below your target level, restart the two part (both parts) at a low dose. Don't use the buffer.