Help with DIY Sump/Fuge

[ticklem]

Ok guys I need some input from the experts . Since I have my stand 95% done I am moving on to the next part of my 40Breeder project. I have decided to go with 1 corner overflow with the overflow and retun pipes going thru the bottom of the tank. ( and no it is not tempered glass). The overflow will be 1" and return 3/4". This being said I am trying to get the best design for my Sump/Fuge area. I will be using my old 20L that is my display tank now. I am attaching the best configuration that I can come up with and a very good article that I found on the subject. Please give me some feedback because I only want to do this once.

Article on Sump/Fuge

 

Picture of what I am thinking

[ticklem]

bump

[Drez]

Looks good. Personally I would have the Cheato and Skimmer in series rather than splitting the water from the tank. In addition to being easier, the way you have it set up they're both working on their own, I would argue that since the point of both is to rob the display of nutrients laden water you might consider having them in series to have the return water as stripped as possible. You'd probably want one, I would guess the skimmer first, to take out as much as it can first and then have the water out of the skimmer going to the cheato to have the remaining nutrients stripped from the water.

 

I've heard argued otherwise but not sure I agree. If the water to cheato was so nutrient poor that the cheato counldn't survive (and Im sure this wont be the case) then it simply means you've achieved your goal and are effectively removing organic waste from the water.

 

If math helps you as it does some, lets assume some bogus numbers, say 20 gal of waste laden water (w) per some unit of time are coming from the tank to the sump. If both the Cheato and Skimmer are able to reduce w by say 50% (thats reducing the waste in the water not the water itself ) then having the sump set up as you do would result in T=(10w(0.5)+10w(0.5), t = 10w, as in every T 20 gallons of water will still be laden with 10w which will be returned to the tank. Having the Cheato and Skimmer in series might result in t= (20w(0.5))0.5, t=5 meaning after t, 20 gallons will have only 5w remaining in the water sent back to the tank.

 

That's obviously an oversimplification as there are other factors (i.e. skimmer might not be able to handle the volume of 20w*0.5 or Cheato might not be as efficient after the skimmer has stripped some of the waste from the water and might only manage *0.3 vs *0.5 but it illustrates the point that you'll likely send water back to the tank with more waste removed in series that in on their own.

 

Thats how I see it anyways. HTH

[bitts]

 

let me first throw this up. its the other basic modle to build the sump off of. other than the one you have posted. there are reasons to go with both, mostly it comes down to your take on how to run the fuge. but I'm getting ahead of my self. there is yet much to determine though, about the end goals for the sump. first let me state that I am very biased as to the design & construction of sumps. I firmly believe that the drain is part of the sump. that the sump even extends into the display so far as the choice in substrate. fore it is a critical part of the filtration. that the water flow should pass entirely through the skimmer or as much as the skimmer can handle. that this should happen a certain number of times a day (there are formulas for finding the gph to achieve this). that skimmers should go before the fuge. so on & so on.

 

I always like to establish the known bioload before working on the filtration. so as to cover all aspects, as well as there interactions. for example the choice of drain changes the amount of surface skimming. which seems trivial, yet can have a substantial effects on the skimmers performance. if this is known it can be factored in.large fish loads can lead to ammonia immediately after feedings. blah blah.....

 

 

the argument for chamber placement.

first lets just skip the argument about weather or not to have a fuge for now & move into sumps with a return chamber, fuge, & skimmer chamber. so lets start with placement. really IT DOESN'T MATTER. sure some ways will accomplish things faster than others. but don't let people step in & start dictating things simply because its there opinion. YES THAT INCLUDES ME. as to where should the fuge be in the sump. after the skimmer makes sense so that the pods go to the display. but other than that ehh... I've seen it argued that the fuge should be separate so that dirty water can be sent to both, that it should be separate so that water can be sent to the fuge at a controlled rate. or to increase dwell time. all have merit but I will point out that skimmers remove doc & particulates. where macros pullout phosphates & nitrates. as for dwell time, in the immortal words of Fosi. its a closed f#####g system, how do you plane to increase the dwell time. sure the water could sit in the fuge longer but what matters more is the contact between the nutrients & the plant (really the only way to up the dwell time is to shut off all the pumps.). the volume of water passing through the fuge will normally have little affect on this since most run power heads to maintain proper flow across the sand bed. so its more of a ? about how you want to do things. give small portions multiple times of contact or process larger volumes while having fewer opportunity's for contact during each pass. sort of like recirculating skimmers vs big downdraft monsters, both work & are more affective at higher concentrations. (effectiveness at higher concentrations being the argument against recirculating skimmers in favor of downdraft or regular skimmers). one argument that I would put in as being worth thinking about. is that the skimmers recommended water depth would/could require the sumps water line to be lower than desired. due to the skimmers height. so placing the return chamber in the middle allows the fuge to use the sumps full height. there's a book called Aquatic Systems Engineering: Devices and How They Function by P.R. Escobal. that I have yet to get my hands on. damn thing is worth a small fortune at this point since its out of print.

but the formula from it about the rate things are processed is...

 

cut & paste from http://www.hawkfish.org/snailman/skimmer101.htm

 

T = 9.2 (G/F)

 

Where T=time, G=total gallons of tank water, and F=flow rate (gph). The 9.2 is a purity coefficient that when used in this equation yields a 99.99% purity. For further explanation of this, please refer to Escobal's book.

 

the equation shows diminishing return as filtered water is returned to the system. then based on this, knowledge. how long is needed to processes the entire system volume. I've based my thinking for both skimmer & fuge on this concept. but ehh...

 

as to drains

well as most will know I'm the president of the herbie fanboys. but thats because the system works. theres more to it than just a silent drain so you can sleep. it also prevents salt creep & micro bubbles from pasing through the sump. beyond this it improves the, well enables, the drain to be feed into the skimmer. with out running air into the pump. you still need a hartford loop or other form of bubble trap to protect the pump during the few minutes after startup, when there is air in the drain. but overall is a great improvement.

 

baffles

a 3 baffle design is always going to be the greater performer, how ever a single baffle with foam/sponge is a close second. plus allows for the space to be allocated to other area's of the system. the distance between the baffles determines the flow rate through & thus the likely hood of bubbles being pulled through. so the more flow you expect to push the more space this will take up. also the otherr con besides wasting space with the three baffle setup is the accumulation of detritus with in the baffle.

 

overflows

well I'm not going to put to much emphasis on this, beyond. the length of the weir determines the ability to provide surface skimming. this improves the surface boundary layer for gas exchange. increases skimmer production. from this the most effective over flow becomes the coast to coast or the external coast to coast. my preference due to the added display volume & cleaner look. these can be improved upon by the use of a dual sided c2c. but I still prefer the exo for the before mentioned reasons.

this will most likely seem like a small gain. but as alwaays, small steps add up, & the higher concentration of of particulates is what provides the net gain. its mostly seen in the rate the skimmer can pull. shortening the time that these have to brake down in the tank. on rc in the advanced forum the are several threads linked on this topics for further reading now lets move on before the old argument about the need for these small steps rears its ugly head.

 

return levels & water lines

first we need to talk about back flow. the amount of water which returns to the sump when all is powered down. now this amount should always be minimized as much as you can. then calculated so as to have the room present in the return chamber to absorb it. in addition to back flow there must be enough room for evap to take place. this is hard to calculate & can sneak up to bite you on the @$%. in the last sump I built for example. I went from having maybe a half gal a day to nearly a full gallon, which is close to the maximum that the sump can absorb. when figuring this calculate the cubic inches that will be drained. so as to have the same in the return chamber. so on & so on. one last thing, to the best of my knowledge (checked) its 231cubic inches to a gallon. now in addition to all of that if the drain being used is a herbie or bean then as the plumbing fills there is air in it limiting the flowrate causing the water line in the overflow to be Higher, than normal. thus lowering the level in the in the return chamber. this can be reduced through the use of baffles or stand pipes in the overflow it self.

skimmers need a constantly stable water line to maintain performance & not overflow if the water line raises. so even the simplest sumps that run one must have a baffle to accomplish this. one other thing to consider is, the skimmers needed depth. most skimmers will have a recommended depth, which is most easily accomplished by elevating the skimmer it self. by taking this into account you can plan in a shelf to keep the skimmer at the proper height, while creating an area to house other equipment. thus enabling the minimizing of the skimmer chambers footprint.