PDA

View Full Version : How do I tell if I have a Bacteria Bloom or Calcium Precipitation?


Get Hooked
07/22/2013, 08:51 AM
My tank is cloudy, I'm assuming from over feeding, and it seems from all of my reading it is likely to either be a bacteria bloom or calcium precipitation. I haven't measured my Ca, Mg, or Alk lately, but will tonight.

Is there a way to determine which it might be?

eyesinthedrk
07/22/2013, 10:05 AM
it would have to be an awful lot of precipitation to cloud a tank to the point you couldn't tell if it was a bacteria bloom or not. that said one time i had my tank clouded by GFO powder from having too much flow in the reactor for the amount of GFO i was using.

rrasco
07/22/2013, 06:17 PM
For the calcium to precipitate your water would have to be supersaturated.

How much are you feeding?

Another thing that can cause a bacterial bloom is low oxygen. Do you have any powerheads or other means of circulation in the tank? A powerhead agitating the surface of the water might surprise you.

behlke
07/22/2013, 07:45 PM
Fill a glass with tank water. The Ca will settle to the bottom of the glass in 20 minutes. But, if it is a bacterial bloom, the water will remain cloudy. Good luck. And welcome to reef central.

oquockyo
07/22/2013, 07:48 PM
Fill a glass with tank water. The Ca will settle to the bottom of the glass in 20 minutes. But, if it is a bacterial bloom, the water will remain cloudy. Good luck. And welcome to reef central.

Wow excellent answer!!

Sparkpaul
07/22/2013, 07:50 PM
Useful info, thanks

Get Hooked
07/23/2013, 08:57 AM
Last night's measurements:
Ca 520
Mg 1420
Alk 9.3

I filled up a clear water bottle with tank water and it doesn't appear cloudy, only in the tank can you see the cloudiness. I let it sit for 20 minutes, I didn't see any calcium looking deposits settle on the bottom.

If I could visually see the cloudiness in a small sample, I would add hydrogen peroxide to see if it clears, but the cloudiness is imperceptible in small volume.

Also, LFS recommended 100 small hermit crabs to clean up the food on the substrate so I added them last night too. My Naso Tang only eats seaweed and shreds it all over the bottom when he feeds off the veggie clip.

brandon429
07/23/2013, 09:33 AM
Here is five pages just like your thread for other ideas

http://reefcentral.com/forums/showthread.php?t=2308997


This poster had unusually treated rock that we are still trying to eliminate as a source. By unusual, I mean prior dried out and chemically treated vs standard live rock you bring home wet from a lfs and put in your tank. This is a tough challenge if anyone has ideas for the other thread post up we are running dry

dkeller_nc
07/23/2013, 09:34 AM
Last night's measurements:
Ca 520
Mg 1420
Alk 9.3

All of these values seem abnormally high, particularly the calcium value. With a calcium concentration that high, even with that high of a magnesium content, precipitation of calcium carbonate is a real possibility.

One potential reason for all of these values being high is high salinity. If you measure salinity by refractometer, I'd recommend purchasing a calibration solution in addition to the usual calibration adjustment with RO water.

Get Hooked
07/23/2013, 09:46 AM
All of these values seem abnormally high, particularly the calcium value. With a calcium concentration that high, even with that high of a magnesium content, precipitation of calcium carbonate is a real possibility.

One potential reason for all of these values being high is high salinity. If you measure salinity by refractometer, I'd recommend purchasing a calibration solution in addition to the usual calibration adjustment with RO water.

My salinity hovers between 1.024 and 1.025 using a refractometer. Perhaps a 10 gallon water change is in order. I battle low pH, perhaps adding kalkwasser to keep pH near 8.0 is adding too much Ca with nothing in the tank to deplete it? My pH seems to be around 7.7 without kalkwasser. Still can't rule out bacteria bloom though...

dkeller_nc
07/23/2013, 10:29 AM
The actual calcium content of saturated, settled kalkwasser is actually quite low, and I would think it's unlikely that adding it for evaporation makeup would generate calcium levels in the mid 500's unless you have a huge amount of evaporation over time.

Regarding the salinity levels, realize that using a refractometer doesn't guarantee accurate results, it depends on the calibration procedure, temperature equilibration, etc... If you don't have a refractometer standard that's near where your measuring, then the accuracy of the instrument may be in question:

http://www.bulkreefsupply.com/aqua-craft-refractometer-calibration-fluid.html

Whiterabbitrage
07/23/2013, 10:41 AM
The Straughan Nose Test usually works! :lol:

Invented by that great fish man and author Robert P.L. Straughan in the 1950's

rrasco
07/23/2013, 10:48 AM
All of these values seem abnormally high, particularly the calcium value. With a calcium concentration that high, even with that high of a magnesium content, precipitation of calcium carbonate is a real possibility.

Only the calcium seems a tad high, but even at that level, it's perfectly acceptable and won't cause precipitation.

dkeller_nc
07/23/2013, 12:24 PM
Only the calcium seems a tad high, but even at that level, it's perfectly acceptable and won't cause precipitation.

What I was referring to was the stated test values relative to natural seawater.

These are normal seawater values:

Calcium: 400 - 420 ppm
Magnesium: 1250 - 1290 ppm
Alkalinity: 7-8 dKh

From the standpoint of the potential for calcium precipitation, that question is extraordinarily complex and greatly depends on the concentration of other ions in solution and the pH, so it is probably not possible to say with certainty whether the calcium will or will not precipitate in this specific tank. But it's certainly possible at a concentration in excess of 500 ppm

rrasco
07/23/2013, 03:51 PM
Fair enough. In this specific case, my gut says bacterial bloom.

Get Hooked
07/26/2013, 03:06 PM
Performed a 20G water change a few days ago and I also removed the kalkwasser from ATO. The water is getting clearer everyday. Today is the best it's been, crystal clear. That cloudiness had me a bit worried. When in doubt, water change time.