A
Anonymous
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I do not think you graph is accurate. Things that get taken out by skimming are added throughout the day. Fish do not poop once a day at a set time. I do see where you are going.
Required sump flow if using closed loop
- Thread starter das75
- Start date
I also don't think the 1% number is accurate at all. And most skimmers move alot more volume.
Mine for example moves 1000gph thru the skimmer.
I really have always wanted to use tracer compounds to see how well skimmers work in a closed system. But it wouldn't be terribly cheap, although it would be fairly easy. Use an isotope of a common element, like N, add it in a given amount from something like a bacterial culture that was raised on it. Add X amount of culture (hence you know how much you have added of N) to the tnak and over time, sample and quantify the amount in the various fractions.
Wade
Mine for example moves 1000gph thru the skimmer.
I really have always wanted to use tracer compounds to see how well skimmers work in a closed system. But it wouldn't be terribly cheap, although it would be fairly easy. Use an isotope of a common element, like N, add it in a given amount from something like a bacterial culture that was raised on it. Add X amount of culture (hence you know how much you have added of N) to the tnak and over time, sample and quantify the amount in the various fractions.
Wade
I agree. But then your cooling/heating rate is limited by certain bounds too... there should be an optimal amount of passover time to get the best effect of temperature exchange. I also think it depends on the setup/purpose of the sump. If you have alot of rock/sand, then more flow creates a better cryptic filter as well.
Wazzel":1wgwyqjl said:
The figure shows the case for constant input throughout the day.
However, throughout the day is not good either: it has to have a period: I'm sure there are more nasty things added when you feed... I can simulate with any input you want (it only takes about 1 minute).
M.
Attachments
wade":3c03jzv8 said:
1% is not the flow through the skimmer, but rather the procent of nasties removed from the water that goes through the skimmer: it is reasonable to believe that not all nasties are removed at once. I assumed (as stated) that the flow through the skimmer is 10x the volume of the main tank (which for you would be 2500gph).
M.
Ok, so lets tighten down what you mean by 1%.
You are predicting 1% of the nasties in the entire system are removed/hr or that 1% of the nasties in the total volume of water moving thru the skimmer is removed?
I would have to argue that with your "average" dissolved organic carbon, you would get much more than 1% of them out of the water column with a good skimmer.
And yes, your predicted flow thru on the skimmer is higher than that on my tank/volume.
You are predicting 1% of the nasties in the entire system are removed/hr or that 1% of the nasties in the total volume of water moving thru the skimmer is removed?
I would have to argue that with your "average" dissolved organic carbon, you would get much more than 1% of them out of the water column with a good skimmer.
And yes, your predicted flow thru on the skimmer is higher than that on my tank/volume.
wade":25zkj4sf said:
The second one, I'm assuming that 1% of the nasties that go through the skimmer are eliminated.
OK, for 10% the graph looks like in the attached picture (as expected the nasties are removed faster and stay close to zero until you feed the tank again).
Probably the proper input is somewhere between pure impulse and all constant... anyway, either way the flow through the sump it doesn't seem to make a whole lot of difference to the level of nasties in the main tank.
Mihai
Attachments
OK, attached is now the result for the more realistic input: some release of nasties (from the fish) throughout the day and one spike per day (due to feeding).
The results is now quite a bit different than before: due to the fact that the skimmer pulls out the nasties faster than before (10%) and the fact that you keep adding stuff the "steady state" for 1x is quite different from 10x: right before you feed the tank you have about 81% more nasties in the tank at 1x than at 10x.
Sooooo, given the right input, the 10x system can be more efficient than the 1x
The main question is now, what is the real typical input of nasties in the tank... and of course an approximate number for the efficiency of the skimmer.
M.
The results is now quite a bit different than before: due to the fact that the skimmer pulls out the nasties faster than before (10%) and the fact that you keep adding stuff the "steady state" for 1x is quite different from 10x: right before you feed the tank you have about 81% more nasties in the tank at 1x than at 10x.
Sooooo, given the right input, the 10x system can be more efficient than the 1x
The main question is now, what is the real typical input of nasties in the tank... and of course an approximate number for the efficiency of the skimmer.
M.
Attachments
I hesitate to call that post on DBW's site stupid... but.
If you do the numbers... they are the exact same in their simulation. 10x vs 5x but 90% vs 45%. Its the exact same thing! Now if they had done that exact same calculation based on both skimmers being equally adept at removing contaminants... say 50% on both, then you would have seen if a difference really existed.
We'll have a better answer when we are done bickering about real parameters.
If you do the numbers... they are the exact same in their simulation. 10x vs 5x but 90% vs 45%. Its the exact same thing! Now if they had done that exact same calculation based on both skimmers being equally adept at removing contaminants... say 50% on both, then you would have seen if a difference really existed.
We'll have a better answer when we are done bickering about real parameters.
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