What I've learned so far.Skimmer stuff
the water column in in the skimmer should be from the bottom up.
water without bubbles, (this may not be visible due to the chamber being black)
there will be a visible point were this changes
then a mixture of water & bubbles
finally a point were the bubbles become thicker & a dense layer of foam will form moving up & down in the neck. this point were the bubbles brake may fluctuate but the water line should be stable.
ideally the distance between the water bubble line & the bubble brake point should be as large as possible. which is why they are is so tall.
source of pic of the 2 pics above.http://www.reefcentr...mp;postcount=30
As to dialing in the skimmer.
The bubbles should be a consestent size through out the coloum. Ideally as small as posable with no turbulence. (this is where adjusting the air volume comes in) Just small bubbles Moving slowly upwards. Finnaly collapsing near the colection cup. This point of collapse will do several things. Wet vs dry skimmate. How quickly sludge builds up on the neck of the collection cup, reducing production.
Most people complane about ther skimmer not functioning due to the fact that in an attempt to get deep dank dark sludge they set the skimmer so that there forms a nice thick chunk of foam in the neck. Sort of like what you would expect on a capaceno. Thick enough that you could float a coin on it. Now I'm not saying this is wrong but there is an ideal placement of this thick foam. The problem that most run into is that in order to get this sludge they never have the foam cap raise high enough to have it deposit anything in the cup. Leaving nowhere for the buildup to collect but on the walls of the neck. Quickly reducing the skimmers effectiveness. Even on a propperly adjusted skimmer the neck needs cleaned every 2-3 days. So having it set corectly is very important.
To set it adjust the water line then the air flow to detrimin the bubble size. then wait an hour or two.
The fun part is getting it to this prefect point. Without overflowing the cup when you turn it back on after powering it of. This mostly comes from having the water line to high with the air to low. This is the other reason why people end up with the miss-adjustment. They just set it to not overflow on startup.
skimmer selection should be based more on bioload than tank volume. this is what allows the foam to form & move up the neck, into the cup. when the bioload is to load, it prevents the foam from forming in a Constantin manner. which results in the skimmate forming on the neck further reducing production. you adjust the production rate of an over powered skimmer somewhat by controlling the airflow. however the waterflow may be more difficult to control with out compromising the skimmers performance.http://www.amazon.co...n/dp/1888381108http://reefkeeping.c...03/fm/index.phphttp://reefkeeping.c...ature/index.phphttp://w3page.com/fi...if/ddskimpz.jpghttp://www.cs.cmu.ed...g_dd/index.htmlhttp://www.hawkfish..../skimmer101.htmhttp://www.thekrib.c...kimmer-ets.htmlhttp://www.reef2reef...discussion.html
speaking of skimmate.Bioload
taking your time & doing the research is smart.
as to feeding. not quite more than they will eat. but but learn to control the level of nutrients produced by the fish through feeding them. most tanks are underfeed to prevent build ups in nitrates & phosphates, but in the macro tank this is what feeds the tank. if you've learned to keep the trates at 0. than the next step is to learn to bring them up & down by feeding the fish, with out losing control of them or relying on water changes. so somewhere between 0 & 5. your standard test kit wont be calibrated for this so you have to use the tank & its livestock to do this. things like lps polyp extension, redslime algae between the sand & glass, algae growth, how quickly the glass forms a film you need to scrape off, consumption of alk by denitrification, growth rate of corals, fish, & inverts, so forth. maby feed that extra pellet you've always felt guilty about not letting them have, or even adding a meal. possibly adding more phyto when you dose. just go back to basic's, after all its all just one big cycle. the better you become at manipulating & understanding the interactions. the greater your tank will respond. just remember that first cycle the tank went through only finishes if the tank crashes. you cant control it, just interact with it like any other living thing. Drains & Overflows
To start let me come right out with my bias is towards drilled tanks.
Link to bean animals silent & fail safe drain.http://www.beananima...low-system.aspx
So first as to how & why.
There are only two ways of taking water from one tank to another. Well three. But we're not counting buckets. It can be siphoned or allowed to flow throw a drain.
There are pro's & cons to both. But let's start with siphons. Others may disagree about the order of importance. but for me the ability to drain a large volume through a relatively small drain would be at the top of the list. Others would be simplicity, mobility, & ease of use. Now the main problem is that they will lose siphon. This is not a question of if but when.
Which bring us to the alternative. Drilling the tank. First putting a hole in the side of a tank means that its almost guaranteed to have the water come out of it. Now the problem with that is you may not want the entire tank to drain at once. As a solution we utilize overflows to wall off the majority of the tank from the drain. But we'll talk about those later. Now as I said its almost guaranteed to drain. Which means that it could become clogged. But that's the only way to prevent the drain from working. As a solution we add secondary drains to work as back ups. Just in case. Which means that you no longer need to worry about wet floors.
What size holes do I need for the drain and the backup?
1.) To start there is a relationship between drain size & flow rate. Flow rate is acheaved by the height of the water line above the drain, combined with the size of the drain. I.e. The more water & the larger the drain, the greater the flow.
2.) How much flow is wanted through the sump/fuge. There are great debates over what is the ideal flow, but a fuge needs a high dwell time for nutrient transfer. So maby, as much as it pains me to use the term, 5xthe size of the fuge for turn over. Flow can be met by powerheads. Simple sumps have no limitations on there flow behyond micro bubbles, heaters, & skimmer performance. In the over flow thread there I have a link to a flow rate calculater. I'll see if I can add the link here with the blackberry if not will do later.
3.) More than likely it will be either a 3/4" or a 1" drain, pearsonaly I like to use the same size drain for both drains. But here's that relationship coming back. As you move the drain closer to top of the tank, the less flow it can handle. So the backup has to be able to handle grater flow than the primary if & when the the drain clogs (Yes the drain will clog). This helps to set where the drains will be Placed. The distance between, height within the overflow, & so on. The back up needs to be low enough to drain while still not having the overflows water line go above the weir (you knew I'd work it in there some how, fancy word for were the water flows over). While the primary needs to have enough distance between its self & the backup to be fully submerged with out creating a vortex sucking bubbles into the drain (that's what makes noise).
4.) When drilling tanks. There needs to be, at minimum, the diamiter of the hole between the hole & the edge of the panle being drilled. This is the minimum to not crack the glass. More is better. So figure out how much you want through the sump/fuge. Then put the backup as close to the weir as you can & still achive this flow. Then put the main as low as you can with out cracking the tank. Set water line in overflow with ball valve or gate valve.
What size hole for the return?
1.) This will most likely be the same as the output of the pump. Would expect 1/2" or 3/4".
2.) 3/4" or 1" return plumbing can be split then reduced to 1/2" as it enters the tank.
3.) Without siphion brakes, or other messures to prevent backflow. The tank will drain to these returns when the pump is shut down.
What pump recommendations? (I'll be running an MP40 for the main tank flow)
1.) Normally the least expensive to run. I hate spending money I didn't need to. I run quiet one pumps for this reason. But to be dead silent eheim is supose to be the best. Untill you steep up to exo's like iwaki (the pretty japaness one) or gen x (the knock off)
2.) Eductor nozzles can reduce the size of pump needed to reach a set flow rate without effecting the drains. (Free flow)
3.) Never reduce the flow to a pump this will cause the pump to cavatate (bubbles).
4.) When picking the pump remember to judge it not only on flow rate but head.
What plumbing parts do I need to pull this whole thing off and where's the best place to get them?
1.) Welcome to the never ending trips to homedepot. Most plumbing will be found at the local box store. Speicalty items like bulkheads will be at the lfs.
2.) Peaces parts Vynal tubing Hose barb fittings (sevral types. 90? Mpt for the main, reg mpt's for most everything else)A couple feet pvcTeflon tape (this is your new best friend. Use a lot & once you have tightend the fitting will need to be replased if lossened)Bulkheads & screens (no open pipes)Pvc solvent90 elbows & other pvc partsBall valves/gate valvesQuick conects/true unions
3.) Air leaks will cause asperation (bubbles) make sure to have all joints sealed tight.
There are pics of my old ten x ten in my tank thread & more info on water in my sig. Hope this helps.
stabilizing the water line can be done through just the one drain. if the back up is used with just a trickle it will be silent & easer to set but the evap can triple. mine takes 12-15 min to stabilize after startup. the ball valve will "stick" after its been sitting for awhile use a sharpie to mark a ball park reference point once you've got it to just a trickle after a couple min stabilizing. you should be able to tweak it from there. once the air is out of the main drain line the water will start to flow at a slightly higher rate allowing the water line to slowly drop. its this lowest point that your trying to set. to make your self feel better find the flow rate on your pump minus head. then take that to find the proper height to place the backup drain. it will be the flow rate of size x drain @ y inches of water above the drain. so if your 1" drain needs __ inches of water above it to flow at the same rate as the pumps out put. set the backups stand pipe to be a couple inches lower than that. the flow rate on a one inch drain is pretty good so you shouldn't need that much above the backup. then you set the main drain to be a little lower than the backup. a bean style is setup for overflows without enough room to stabilize the water line without using the backup. like small coast to coast setups.
first a weir is the point where water fslls over the rim of an overflow, dam, wall. The thing with teeth is there's trade offs. That have to do with the flow rate & type of fish. Like clowns can't swim as well as other fish. so with out teeth a high flow may be problematic. But with out teeth the entire length of the overflow can be used for the weir. Evectively lowering the flow rate at any given point along the weir. This reduces turbulence & allows for better skimming with higher light penetration. Right, its a low % that gets mixed back in. But the number of times I saw a piece of food almost get sucked into the drain but somehow avoid it is what got me started in all of this weir stuff. so. There's that. plus This % being low is why there is only a sublte incress to skimming. The other thing is that the boundary layer at the surface is the most important part. While making up a relatively low % of the total water, passing over the weir. The lower the flow becomes at any given point along the weir. The greater this % becomes. Think how much of a difference there would be with a water height of 3/8 vs 1/16 above the weir. There's a bunch of math you can do to figure this % out but its pretty self explanatory once you get the hang of it. If your interested there are links in my sig.the short answer is that you increased the concetration of nutrints in the water being ssent to the skimmer. Anyway this combined with running the drain directly into the skimmer. Is the best improvement I know of to prevent doc from entering the nitrogen cycle after proper turnover has been established. Note that turn over should have nothing to do with the drain rate. Even with out a skiimer this will move the blah to the sump for the next water change.
So with smaller tanks like ours. maximizing the effective skimming ablity while minimizing the size of the overflow is paramount to water quality.
Then in response to using a wave maker in a tank with an exo overflow.
well its kind of catch 22. as you can guess, any type of overflow will be problematic with a wave maker. but the coast to coast can handle it better than others as long as your ok with a few things. the waves will reduce the effectiveness of its skimming capability's. this is why most chose this type of setup. but the water will also be agitated mixing the surface skim into the water column. so this is not as large a factor as it could be.
another thing to consider is that. with a wave system the water will not flow into the overflow at an even rate regardless of type. the water is either moving towards or away from the weir at any given time. which is why as long as the water is moving along the weir there is some benefit to the coast to coast setup. this though can bring its own problems.
ok so with this in mind. know there will always be a noise issue combining an overflow & waves. the water flowing into the overflow at varying rates will set up a wave in the overflow itself. internal overflows are not as affected by this in a negative way, as much as exo's. due to the water volume inside the tank helping to hold the overflow in place. where as an exo if made without proper planning may not with stand the force's this places on it. both of these limits can be met by using a smaller wave.
with the setup you were looking at i would expect it to be fine as long as you didn't go nuts with the wave action. Ive never used anything but the vortechs to make waves but it should be the same.
Will be editing to include items from previous posts. If as always some one can think of something I've skipped speak up.sump design
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..../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.
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.
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.Sand
so the first thing that ive really been able to gleam out of all this is minimizing contact between the rock and sand improves flow through reduced turbulence near the bottom of the tank. which if we can learn any thing from the barebottom era, is the secret to minimizing waste aqumulation on the bottom of the tank. now i know someone's going to say but theres sand its ok. doesnt matter if its a bare bottom tank, shallow sand bed, dsb, dsb with plenum. there all the same thing the bottom of the tank and the tank will be better off if you keep it from having "stuff" all over it. keep it in the water colomn and move it to the skimmer were it belongs.
as to grain size & type.
rember that the largest driffrince between our reef tanks & natural sand beds is the movment of the bed. because of this in reef tanks there needs to be grains from around 1.5-2mm down to silt. if a size is missing or out of proportion than there will be microfauna & or meiofauna missing from the bed. this may lead to the accumulation of unwanted nutreints in the bed, causing a "nutreint sink". due to the rate of accumulation being greater than the rate of consumption by said fauna. remember its the bugs that stir the sand bed for you and prossess the nutreints. the stirring of the sand bed is how the water is moved through it.
as to type agaronite is the best choice. and fine will have higher calcium levels.
Edited by bitts, 23 November 2010 - 05:17 PM.