Water temperature & nitrifying bacteria

[Pondmaster]

As fall and winter approaches the following may be helpful in determining when to shut down and clean filters.

The temperature for optimum growth of nitrifying bacteria is between 77-86° F (25-30° C).

Growth rate is decreased by 50% at 64° F (18° C).

Growth rate is decreased by 75% at 46-50° F.

No activity will occur at 39° F (4° C)

Nitrifying bacteria will die at 32° F (0° C).

Nitrifying bacteria will die at 120° F (49° C)

Nitrobacter is less tolerant of low temperatures than Nitrosomonas. In cold water systems, care must be taken to monitor the accumulation of nitrites.

 

[Telkwa]

Thank you, Pondmaster. I'm printing this one out and keeping it around for reference. I had no idea the biological activity slowed down so much even at the moderate temps. Our pond hovers at 60 to 70 degrees during the summer.

 

[addy1]

Nice post pondmaster

 

[Shdwdrgn]

When you say the nitrifying bacteria dies at 32°, do you mean literally at that temperature, or that they will die if they freeze?

The reason I ask for the clarification is that I live at high altitude, and I believe water here freezes at 29° (I have actually seem my thermometer reading 30° without any surface ice). I keep my pump and filter active through the Winter, and turn on the heater when I start seeing surface ice, so my bio-filter never actually freezes solid.

 

[Pondmaster]

When you say the nitrifying bacteria dies at 32°, do you mean literally at that temperature, or that they will die if they freeze?

The reason I ask for the clarification is that I live at high altitude, and I believe water here freezes at 29° (I have actually seem my thermometer reading 30° without any surface ice). I keep my pump and filter active through the Winter, and turn on the heater when I start seeing surface ice, so my bio-filter never actually freezes solid.

For all practical purposes they die at or around 32 degrees irregardless of a freeze.

 

[koiguy1969]

even ae 40* your filter is little more than a mechanical filter....

 

[carolinaguy]

nitrifying bacteria can actually just go dormant rather than die at low temperatures. more importantly, remember that koi have bacteria in their gut that assists with digestion just as you have, and since koi are a cold blooded animal, those bacteria also shut down gradually. there is a point where koi just are not interested or may eat but not digest. the result can be a koi gut filled with rotting food when the spring warmup starts and the resulting potential for injury and death.

if your pond is mature and has large accumulations of algae on the side, they will graze and derive nutrition from that food source. i had koi last year that actually put on weight from algae grazing, since we stopped feeding at around 50 to 55 degrees. algae has about a 60 to 70 percent protein content, and since it is a water resident food source, it is more compatible with koi digestion than a land based food source.

 

[Pondmaster]

nitrifying bacteria can actually just go dormant rather than die at low temperatures. more importantly, remember that koi have bacteria in their gut that assists with digestion just as you have, and since koi are a cold blooded animal, those bacteria also shut down gradually. there is a point where koi just are not interested or may eat but not digest. the result can be a koi gut filled with rotting food when the spring warmup starts and the resulting potential for injury and death.

if your pond is mature and has large accumulations of algae on the side, they will graze and derive nutrition from that food source. i had koi last year that actually put on weight from algae grazing, since we stopped feeding at around 50 to 55 degrees. algae has about a 60 to 70 percent protein content, and since it is a water resident food source, it is more compatible with koi digestion than a land based food source.

That's interesting. Are you saying then that the nitrifying bacteria does not die at 32 degrees as stated by the laboratories findings at:

www.bioconlabs.com/nitribactfacts.html

 

[carolinaguy]

not saying that at all. didn't read the hypertext you posted. my pond doesn't cool to 32 degrees, and neither does any other with live koi in it. koi can't tolerate water much cooler than 35 degrees for a long period, and the bottom of most ponds with koi that overwinter stay warmer because of the physical nature of water which is heaviest at about 38 degrees. a pond that cools to 36 degrees at the surface is typically about 2 to 3 degrees warmer at depth, and with a circulating pump will be an environment where good bacteria will survive a wintering over by becoming dormant below 50 degrees or so. no argument with your reference at all. the earth surrounding the pond below the frost level serves as a heat sink and supplies some warmth to the water keeping the temperature above freezing, and an ice layer on the surface of the pond, if it ices over, acts as a thermal blanket keeping heat in. i'm just saying that after a winter period, the biofilter in a mature pond will come back to life with a live colony of nitrifying bacteria. now nitrobacter, the nitrite loving organism i think, and correct me if i'm wrong, may well be the less hardy organism. that might explain why i can never seem to get my nitrite level down to zero. if you can figure that one out, please tell me. i've got enough filtration for 200 pounds of fish and can never hit zero even with the 65 pounds i've got. moving bed k-1 with pumped air, matala, bioballs, and a bakki, and the water tests out at 0,25 to 0.5 every week. checked the test kit with a new one and came up with exactly the same value.

 

[Pondmaster]

Didn't have any hypertext link on the first post. Your right on the nitrobacter. Did you check coming straight out of your filter? How many times an hour does your pond water turn over? Where does your makeup water come from?

 

[carolinaguy]

yes, went through the measurement analysis you mentioned. its an api liquid tester, so we can take it as an approximate measurement, but that said, the variance at the filter output is about half an increment or a less compared to the display pond values. definite color difference, so the display pond area has immediate residuals from current waste output. the turnover is typically about 80 minutes. the filter is under modification right now so we restricted the pump flow to probably more like every two hours, but it appears that at 80 minutes or 120, the nitrite values are the same. a meter like a milwaukee would give a more accurate reading, but we are changing other things, so that will have to wait. i thought when we added the bakki, there would be a change. nada.

i'm starting to believe that nitrite levels at zero are reported from other ponds due to no real measurement, mismeasurement, or a need to report what everyone else reports. or i'm doing something to degrade colonization. we clean weekly, and its an open filtration system. no city water spray in the process, and i never disturb the k-1. i just open the bottom valve and flush bottom sediments. i did notice that when taking an api measurement, nitrite color change is slower than ph and ammonia. maybe folks report values before the indicator completes its color change?

 

[shakaho]

That's interesting. Are you saying then that the nitrifying bacteria does not die at 32 degrees as stated by the laboratories findings at:

www.bioconlabs.com/nitribactfacts.html

The article states,"each strain may have specific tolerances to environmental factors and nutriment preferences not shared by other, very closely related, strains. The information presented here applies specifically to those strains being cultivated by Fritz Industries, Inc."

As a biologist, I cannot see how it would be possible for the nitrifying bacteria in the soil and water of the north to die out at 32 degrees F. They are obligate aerobes, and thus only survive where there is oxygen available, and both the soil and the water freeze deep. Pampered laboratory strains may well be different.

 

[carolinaguy]

shakaho, the idea of an obligate in its natural environment, a wild strain, dying out because of temperature only is implausible. in addition to that these aerobes also can become dormant spores according to my references, and in an anaerobic environment, like a sealed filter when a pump is turned off for more than 45 minutes and the oxygen is exhausted, these little critters are actually supposed to switch to an anaerobic mode for survival and then switch back when oxygen is supplied. pretty tough little guys in the wild. its plausible that an inbred lab strain might be less viable under stress.

got any ideas about how to add to the nitrite loving population in a filter? i can't find a reference that suggests a way to bump up that population.

 

[Pondmaster]

Wow! alright I'm impressed:lol: Have you tried Microbe-lift bacterial inoculant? Lot of ponders here use it.

 

[carolinaguy]

Pondmaster. thanks but not impressive. i just read a lot. yes i use microbelift. doesn't change anything. one microbiologist says the stuff can't really be shipped, but i don't buy that. i've researched the products and according to the guys at Strata, microbelift's rotten egg smell is added to the product for the sales guys to use as a sales point. they don't have to make a hydrogen sulfide smelling product. strata's competitive product doesn't smell. the only live shipped product out there is Strata's AWT-1 used by the big commercial aquariums like Seaworld, but it costs $170 a gallon and is shipped in a cold pack. supposed to bring a pond up in 24 hours.

i just wonder if its possible to find a natural source other than filter crud from someone elses pond to bolster the nitrite eaters. the farmers use horse manure as start up stuff or chicken grit.