Alkalinity parameter

[jmsilhy]

Hi everyone, I've read a lot about keeping Alkalinity at around 8.3 and don't mind the PH so much. Supposedly the salt mix I used (with RODI) in my newly established tank (Reef Crystals) has an Alk of 13 dkh.

My tank has been running for 3 weeks, with the following parameters as of today:

NH3 < .15
NO2 ~ .1
NO3 ~ 2.5 ppm
SG ~ 1.024
Temp 80 deg
PH = 8.3
KH = 6.7 dkh

My plan right now is to slowly increase the Alk and a calculator indicated around 3.6 tbsp of baking soda should do the trick, which I plan to add over a period of 3 days. I only have a few inverts, snails, mini hermits and a shrimp.

Is this a good plan, and what can be the cause of the low Alkalinty?

Thanks!

 

[Sk8r]

Better than baking soda is Alkalinity Buffer ---I use Kent Brand. The buffer will stabilize it. You didn't list your magnesium or calcium. If the calcium is 420 and the Magnesium is, say 1350, your alk will stay up when dosed to an 8.3. Your other readings are fine. But Magnesium and Alk are linked: If you don't have any stony coral or clams sucking up the calcium in the tank, it'll stay put at 420 for a very long time. Your magnesium will run out slowly, really slowly, but if it falls below 1200, your alk will start sinking right along with it. The 1350 gives you some wiggle room where nothing is going to be an emergency. Your fishes' slime coats which protect them from parasites are dependent on that nice comfy alk level.

 

[jmsilhy]

Awesome Sk8r thanks. I will test for Calcium and Magnesium tonight.

 

[jmsilhy]

Calcium is at 480 and Magnesium at 1260.

Is the Kent Magnesium good too (for later)?

 

[Sk8r]

Kent Mg is what I use. Your cal is high enough, no problem. Your mg is enough to stabilize the alk, but kick it up to 1250 or 1350 to give yourself some margin: 1200 is the mark NOT to fall below, because the alk will start to drop after mg falls under 1200.. And after that, you just check the numbers once a week and make yourself a little list---salinity, alk, cal, mg, and watch the behavior of the numbers over a couple of months, also noting any acquisitions or demises. That will establish good testng habits and inform you how slow or fast your tank depletes one of those numbers, and anything that may have resulted from adding some critter, or any distruption like a power-out or such. That should see you through years of good maintenance, knowing how your particular tank reacts, how slow or fast, and to what degree.; That will eliminate a lot of worry.

 

[jmsilhy]

Once again, my most sincere thanks Sk8r. You've really made this hobby a lot easier to understand and lower mistakes/worry.

 

[Sk8r]

Glad to help.

 

[jmsilhy]

Glad to help.

After a few days, I finally got to 8.3 alkalinity. The following day I tested again and it dropped to 7.7, maybe because my skimmer overflowed a few times (for other reasons) and I topped off with new salt water and the ATO did it's job adding some RODI water. I kept the salinity in check.

I dosed buffer again, and this morning it's back up at 8. Should I just continue this until it stays put at 8.3?

My last test parameters on Sunday were: Mag 1350, Cal 440, Alk 7.7, Nitrate 2.5, Phos .1 and 1.024 sg.

(I only tested Alk the last few days-> Mon 8.3, Wed 7.7 (dose again), Thur 8.0)


Thanks!

 

[Sk8r]

Tiny dose of buffer. Yep, minor water crisis, nothing damaging. Happens. Happens more frequently when you're just starting out, (few escape having one at that stage) which is why slow stocking is good. Gives you a lot more safety in coping with bouncing parameters. You're doing ok, just fining up the chemistry to a stable point