Ok here is my math on Bio Media - Argument against pot scrubbies.

[vanilla__gorilla__]

if you want to go cheep bio filter you should look in to diy fbf

I use liters of Eheim Pro media on my 180 may be over kill for a 180 but it will be way under kill for a 1000

 

[VLDesign]

you dont believe 3 l of anything will handle 1000 gallons do you ???

Yes my mistake.. I meant to state 3 5l boxes.. So it's actually 15 liters of media.

That's what happens when I post too late.

 

[Bud8Fan]

the pores get filled with crud, one plus for scrubbies.

I'll second that motion.

 

[VLDesign]

They might get filled with crud sitting in a canister with 900 GPH flowing over them in a media bag, but how about in a sump with 4000 GPH flowing over them?

To help contain them I am looking into some sort of eggcrate type box/container that the openings are obviously small enough to keep the media from falling or flying out but still let the 4000 GPH flow freely.

 

[VLDesign]

Its not that I want to go cheap I just don't want to waste money.

 

[VLDesign]

From my readings 5-6x seems excessive, although would love to learn more if you have a pointer.
http://www.russellwatergardens.com/metabolization.htm

I tested this out when I did mine, during a fishless cycle. I bought double the scrubbies that I thought I really needed for 210 gal (ie: 400 scrubbies). Once the bacteria colonized, it brought down 4ppm (considered by most more than any real load in a day) in less than 8 hours.

So in reality, I probably only needed 1/2 of that and then fully stocked I'm probably not even close to 1-2ppm. So I'm going to imagine those 400 scrubbies could easily do (210*2)*2.5, or close to your 1000. So if I were to double that 800 (ie: security and still under $100) can't see it having issues with 1000, but again I would test it for 4ppm (or your actual load) before you bet on my (wild) guess - grin.

BTW: Eheim Pro media is great; I used it extensively for years in my 2217's, with well-over stocked tanks. The only down side is that you have to replenish them, as the pores get filled with crud, one plus for scrubbies.

Ed

This is some good info.. Thanks..

Also I went to that site and got this formula from there... Which looks like more that what I originally estiamted

1 gram of fish waste is created from 3 grams of fish. (1 to 3 ratio)
So if I wanted to keep 12 pounds of fish in a 1000 gallon system I can expect 4 pounds of poop a day.

How much fish waste can your filter metabolize in 24 hours?​

Biological filters metabolize an average .2 gram of fish waste per square foot of media bacterial Specific Surface Area (SSA) per day. (.2 to 1 ratio)

Total SSA x .20 = Total grams of fish waste the filter can metabolize in 24 hours​

So to figure out how much SSA or media I need to support the 12 pounds of fish I simply change the forula the solve for SSA since I know the total fish waste. (BTW it's 454 Grams per pound) So SSA=(454x4)/.20 and I get that I would need 9080 SSA or square feet of surface area on the bio media.

 

[Dr Joe]

Under ideal (laboratory) conditions.

 

[cchhcc]

True but until someone can produce a bio load caluclator the gallons of water to media ratio is the only starting point.

I disagree. You cannot post an accurate and specific calculation when the primary variable is not calculable. Therefore, it seems there is no "starting point" for your hypothesis.

In your second example (1 to 3 waste production ratio), you must account for the types of waste and their degradation times. For instance, fish do not produce anything near to 1:3 in solid waste, but they do produce ammonia, etc. from respiration and other metabolic processes.

Also, there is no value assigned to various filtration methods (e.g. wet/dry is more effective in the same area as submerged), dwell time, etc. In your example of 4000 GPH, you will not achieve high nitrification rates unless the biomedia takes up a great deal of space. A lower flow, and longer dwell time, would produce better results.

Interesting discussion...

 

[LiquidWare]

There's also no value in the formula for the substrate, plumbing, etc ... that is also a factor in the total biological filtration.

 

[johnptc]

A lower flow, and longer dwell time, would produce better results.

why ???

if it flows at 100 gph it has twice the dwell of 200 gph

BUT it also only passes 50% of the water.....

dont the two effects cancel ???