I was just curious. I have bought my first skimmer about 2.5 weeks ago and it has been running nicely on my 150 gallon FOWLR. When I clean the cup the gunk in there smells horrible. Smells exactly like sewage. Then when I said that I realized well thats exactly where the idea of a P skimmer came from.. sewage processing. Then I thought why is this techinique used with freshwater???? our sewage plants are fresh water. Why do people not use this on those large cichlid tanks who have a huge bioload. Would a Protein skimmer be just as effective??? Would it really make water changes a lot less in a large cichlid tank???? I really think I might experiment this on my 75 gallon Trimac Cichlid. He is about 14" and about 2.5"-3" thick and a solid 5" tall. He's a beast and eats about 20 large pellets a day. His waste is incredible and I waste vacuum and water change 50% weekly. Does anyone think this will work???
Protein Skimmer Debate
- Thread starter Chago09
- Start date
GoingPostal
Active member
They don't work in freshwater, don't know exactly why but I'm sure someone here does...
silverwolf72
New member
From what I've read they don't work with fresh water due to point that the bubbles do not hold together like they do in salt. With a different designed skimmer it probably would work but the ones we use are made to work with saltwater.
jvetter
New member
In wastewater treatment this process is called Dissolved Air Flotation (DAF).
I never tried skimming fresh. I remember reading an article a few years ago about using a skimmer for fresh. I recall the opinion being that it will work, but not nearly as efficiently as it works in saltwater. Air bubbles in saltwater tend to be much smaller than in in freshwater. The surface area/volume ratio of the air bubble is key to efficiency.
Sounds cool to me. Go for it.
I never tried skimming fresh. I remember reading an article a few years ago about using a skimmer for fresh. I recall the opinion being that it will work, but not nearly as efficiently as it works in saltwater. Air bubbles in saltwater tend to be much smaller than in in freshwater. The surface area/volume ratio of the air bubble is key to efficiency.
Sounds cool to me. Go for it.
silverwolf72
New member
I remember reading somewhere waste treatment use a process of forcing air into the water under pressure then when the pressure is removed thats where the bubbles come from. Think like a carbonated soda.
reeftanker04
Premium Member
I think the reason has something to with the specific gravity of freshwater.
alexb518
New member
ok, yeah...it will produce some bubbles, but not the micro bubbles seen in a skimmer. and you wont end up with foam. fresh water is a lot less dense than salt water. besides, why would you need a skimmer for fresh water? you don't have to worry about your water being dirty; you can just walk over the the tub and fill up some buckets for a water change. you don't have that luxury here. it costs me $$$ and a trip to the lfs everytime i want to do a water change.
alexb518
New member
ok, yeah...it will produce some bubbles, but not the micro bubbles seen in a skimmer. and you wont end up with foam. fresh water is a lot less dense than salt water. besides, why would you need a skimmer for fresh water? you don't have to worry about your water being dirty; you can just walk over the the tub and fill up some buckets for a water change. you don't have that luxury here. it costs me $$$ and a trip to the lfs everytime i want to do a water change.
It won't work with anywhere near the same efficiency as in saltwater but it CAN work in freshwater to some extent. It'd probably only help in very dirty tanks. I remember hearing about somebody who had a large skimmer installed on a koi pond which actually worked in helping keep water quality good. It's certainly worth trying on a cichlid tank if you've got a spare skimmer lying around.
Spleen
Spleen
daven
New member
Here is a description of the process they use in "fresh" water sewage treatment. Not the same thing as a simple protein skimmer in saltwater .
Raw water enters the plant where it is initially dosed with a coagulant like metal salts (mostly ferric chloride or aluminium sulphate) to coagulate to break the double charged layers around the contamination in the raw water. During intense mixing small flocs are created, which then will be treated with a flocculant the create larger flocs. The water then will pass into several flocculation tanks depending on the process. The chemical like could be other than alum and even the scheme could be implemented without any chemical depending on process to process. The process of dissolved air generation and separation is identical as observed in aerated water bottle. This is where the DAFF process differs from the sedimentation process.
In the typical sedimentation process the flocculant (floc particles) - the coagulated material - is allowed to fall to the bottom in large sedimentation tanks. In the DAFF process, high pressure product water (from the end of the plant) is saturated with air and then released up into the flocculation tanks. This causes a sudden pressure drop which releases small bubbles of air. These bubbles effectively 'lift' the flocculant to the surface of the flocculation tank. This flocculant then remains on the surface where it is either scraped off or overflows (by deliberate raising of the tank water level).
The water then travels down through a filter which is typically either sand or multimedia (anthracite-sand-gravel). This removes any floc particles which didn't properly rise to the surface.
The rest of the process is the same as the sedimentation process whereby the sludge (floc particles and water) is further dried and then this water (supernatant) is returned to the front of the plant. Also, the product water is then adjusted for pH and fluoride added. Note: these two steps may differ slightly between plants (e.g. sludge put down the sewer where it is treated).
Raw water enters the plant where it is initially dosed with a coagulant like metal salts (mostly ferric chloride or aluminium sulphate) to coagulate to break the double charged layers around the contamination in the raw water. During intense mixing small flocs are created, which then will be treated with a flocculant the create larger flocs. The water then will pass into several flocculation tanks depending on the process. The chemical like could be other than alum and even the scheme could be implemented without any chemical depending on process to process. The process of dissolved air generation and separation is identical as observed in aerated water bottle. This is where the DAFF process differs from the sedimentation process.
In the typical sedimentation process the flocculant (floc particles) - the coagulated material - is allowed to fall to the bottom in large sedimentation tanks. In the DAFF process, high pressure product water (from the end of the plant) is saturated with air and then released up into the flocculation tanks. This causes a sudden pressure drop which releases small bubbles of air. These bubbles effectively 'lift' the flocculant to the surface of the flocculation tank. This flocculant then remains on the surface where it is either scraped off or overflows (by deliberate raising of the tank water level).
The water then travels down through a filter which is typically either sand or multimedia (anthracite-sand-gravel). This removes any floc particles which didn't properly rise to the surface.
The rest of the process is the same as the sedimentation process whereby the sludge (floc particles and water) is further dried and then this water (supernatant) is returned to the front of the plant. Also, the product water is then adjusted for pH and fluoride added. Note: these two steps may differ slightly between plants (e.g. sludge put down the sewer where it is treated).
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