Beneficial Bacteria

[ZmanArt007]

Helllo.

I've noticed that many biofilters seen on here are completely full of water. This confuses me, because I always thought that most beneficial bacteria is aerobic, but most of the filters here seem to focus on anaerobic bacteria... Am I wrong about aerobbic bacteria, or do I not fully understand your filteration systems?

 

[koiguy1969]

the flow thru our filters is plenty fast enough to maintain oxygen levels sufficient for aerobic bacteria to live and flourish...its not as tho the water is idle its continuously flowing thru...true anaerobic bacteria is the bad bacteria, it flourishes in low and no oxygen enviorments and creates the smells that can get quite bad as in the sultur or rotten egg smell. as thewater falls back into the pond it aerates the pond water volume and the water going thru the filter is from the aerated pond.

 

[DoDad]

This is a good reason to aerate your bio system.

 

[koiguy1969]

yep.....i always do!

 

[stroppy]

the flow thru our filters is plenty fast enough to maintain oxygen levels sufficient for aerobic bacteria to live and flourish...its not as tho the water is idle its continuously flowing thru...true anaerobic bacteria is the bad bacteria, it flourishes in low and no oxygen enviorments and creates the smells that can get quite bad as in the sultur or rotten egg smell. as thewater falls back into the pond it aerates the pond water volume and the water going thru the filter is from the aerated pond.

yes i know only too well what a stink you can get in your filter if you dont aireate...mine was awfull before i added an airstone

 

[MikeyToo]

I use this simple ABS plumbing venturi to help oxygenate water going into the bottom of my Skippy biofilter. It's not sophisticated but it works.

 

[ZmanArt007]

I'm a 15-year-old with few plumbing experiences... What the heck is a ABS plumbing venturi?

 

[Squidhead]

ABS is a plastic material used for pipe and fittings, it is usually black in color. PVC is the white ( primarily white, but it comes in different colors also ) plumbing pipe and fittings. A venturi is used on a pump, in this case in the plumbing of the pipe. It is an open vent like this ABS one or even smaller tubing. The momentum of the water sucks air into the water flow. The air forms bubbles and bounces around in the water in the pipe and filter in this case. As the bubbles pop in the water it releases oxygen ( and whatever else is in the air ) to saturate the water with the oxygen. Very effective for it's purpose. The bubblers/diffusers probably don't do this as well, but have many other benefits. To name a couple - It helps with water circulation in bottom drains to bring crud towards the drain and as it is doing this helps circulate the cooler bottom water with less oxygen towards the top and the top layer of water gets sucked towards the bottom. This allows oxygen to get to the bottom and cool the top water on hot days. Just the opposite on cooler days.

 

[MikeyToo]

Squidhead described it perfectly.

I understand the physics of how water passing by the open directional vent creates a vacuum and pulls air into the flowing water. However, what surprised me in this case is that there is absolutely no back-flow of water up into the air opening of the venturi. This surprises me because the 2"PVC pipe carrying water flowing down into my Skippy biofilter goes down about 2' into the stock tank where the end opens up to allow the water to flow back up through my bio-media. I thought surely that the pressure of pushing the water down into the stock tank would cause a back-flow into air opening of the venturi. In fact, when I first installed this I had a 2.5' long PVC "chimney" attached to the ABS venturi believing water would get pushed up that high. To my surprise, such was not the case at all. I clearly don't understand all the physics involved.......

By the way, credit for this type of venturi belongs to my son who added it several years ago without my asking. He was an engineering student at that time and clearly understood physics better than his old man.....

 

[JustMe]

Mikey, don't you love when your kids grow up to be as smart as they thought they were when they were 15!!

 

[koikeepr]

Lol!

 

[3qtkidz]

So does that venturi part really work. I am putting it all together this morning. I guess, I better add this now instead of saying "I wish I would have done that"

 

[koikeepr]

Don't bother with a venturi. A good air pump will give you way more benefit IMHO.

 

[koiguy1969]

thats not even a true venturi..its benefits will be minimal at best. a venturi must be a reduced diameter tube sealed into the larger pipe and the vaccuum pulling from inside the center of the water flow to get its greatest pull of air into the water flow. the condensed concentration of air mixes and multiplies the velocity as it leaves the venturi.heres a sloppy but understandable cut away drawing of a venturi
the video is a proper venturi with a tetrapond 425 gph pump powering it....notice the abundance of air being pumped into the water....imagine 1200 or 2000 or more gph put thru it.
[ame]

 

[Squidhead]

My opinion is a venturi is more efficient for O2 saturation. There are pro's and con's to each. But for overall cost and performance a venturi would be the better choice if the only purpose is O2 saturation.