nineball
Active member
Now I'm confused......I have the shut off valves as you described them off the main trunk. Now I'm trying to understand Mr. Wilsons comment.
Peter
Coral Tank from Canada (1350gal Display Tank)
- Thread starter nineball
- Start date
- Status
Now I'm confused......I have the shut off valves as you described them off the main trunk. Now I'm trying to understand Mr. Wilsons comment.
Peter
mr.wilson
.Registered Member
In addition to control valves at the manifold, you can snap on some Lockline valves that are compact and unobtrusive.
Every valve you use restricts flow even if it is fully open. A properly engineered manifold will increase pump output.
jimicasper
In Memoriam
yeah what he said!
Briney Dave
New member
sounds like a good plan, Thanks so much for your time Mr.W
KingNeptunesBou
New member
Beautiful aquarium! Keep more information and photographs coming.
mr.wilson
.Registered Member
As I said before, the return and closed loop manifolds are similar to the exhaust manifold on your car... all you need to know is to not touch it when it's hot
mr.wilson
.Registered Member
People ask me all the time "how much flow do I need to the sump", "where should I put the overflow box", or "where should I locate the return lines". The answer is never simple because each aspect is directly affected by the other. I like to start at the beginning and look at what the protein skimmer's demand for flow is.
Let's take a step back and think about what we are trying to accomplish before we decide how we want to get there. The main purpose of moving water from your display tank to the sump is to process it in a protein skimmer, and a few other devices. The same process that goes on in your protein skimmer occurs with your surface skimmer. You are separating oils/surface active agents (surfactants) from the water. You have to treat the display tank like an oil slick, but not how the BP engineers and shareholders do
When skimming oil, you want to use a very thin "scoop" so you collect concentrated oil, and as little water as possible. You can accomplish this in two ways. 1) Set-up a surface skimmer that has a maximum amount of surface area. A surface skimmer with no teeth will have double the surface area and subsequently collect water that is twice as concentrated with surfactants.
2) Use a return pump that has a relatively slow flow so the water cresting over the overflow box is half as thick = twice as rich in surfactants.
Both of these factors influence the surface tension of the water travelling over the surface skimmer wall. The overflow box works the same way a water strider bug (those bugs that float and walk on still water) increases the surface tension of the water under it's legs. The teeth in an overflow box increase the water tension in the same way thus limiting the free flow of water over the box. This effect is in addition to the shear surface area of the box diminished by having the teeth.
A better barrier for overflows than teeth is an eggcrate strip that sits parallel to the overflow box wall, positioned 3/8" back toward the box and away from the tank. Any snails will be stopped by a single continuos 3/8" horizontal slot, rather than many 3/8" vertical teeth. I like to use eggcrate because if the entire slot somehow magically plugs, the overflowing water will rise up and find its way through the holes in the eggcrate. This method compromises nothing, while more than doubling overflow efficiency. Unlike teeth, a single slot is unlikely to plug with filament (hair) and macro algae.
The set-up I like for return plumbing, uses end to end flow across the surface as I described in the earlier post. If you are already committed to a central (back wall) coast to coast overflow, then you would be best to use about 4 return effluent ports, all located at the bottom of the tank at the back panel pointing forward, toward the front panel. Make sure you have good siphon break holes or a check valve siphon break above the water level (flap pushed closed while water is on, and flap dropping open letting air in when water flow is off. This configuration will give you a barrel role effect (circular flow), with water mixed well before it is surface skimmed. Water goes along the substrate, hits the front wall, travels up the wall, and then across the surface to the overflow on the back wall. This kind of a set-up works best for jellyfish tank kreisels and pseudo kreisels where the corners are curved to help with inertia/kinetic energy (less resistance).
As Golf Nut pointed out earlier in the thread, an L shaped tank like Peter's needs to be fed at the centre with all ports pointing toward the overflows at either end. You have to treat it like two tanks stuck together in the middle. If you don't go this route, you get chaotic flow which leaves oils (surfactants/hydrophobic proteins) on the surface that cannot be easily skimmed. You get a "no man's land" in the centre where the surface water sits in limbo, not knowing which way to go. You can do a visual test (look up from the bottom and see if there are oily pools of "stuff" that aren't being turned over or skimmed, in addition to the 30 second flake food test (it takes less than a minute
).In summary, don't use teeth and limit return flow to the minimum requirement which is the throughput rate of your protein skimmer. Any more than that will reduce efficiency of overflows, overtax drains, increase noise of water coming and going, add heat and energy use due to larger pumps, and increase salt creep and microbubble formation in the sump. Return ports are to be tuned with your overflow box to create either end to end flow or a barrel role up and back across the surface to the overflow with its waiting open (toothless) mouth.
:beer: cheers to fishroom almost completed. My bday is on Canada Day so I pretty much cheers everything right from mid June until after the long weekend.
Peter those new pics look awesome. Coming down those stairs will be amazing and so overwhelming with that tank their. It will really be a site to see for all your guests coming down those stairs. Also I notice its a open staircase, meaning you will have light shoot up from the basement every night LOL
Keep the pics coming
Peter those new pics look awesome. Coming down those stairs will be amazing and so overwhelming with that tank their. It will really be a site to see for all your guests coming down those stairs. Also I notice its a open staircase, meaning you will have light shoot up from the basement every night LOL
Keep the pics coming
mr.wilson
.Registered Member
If you really want a magic number it is 1.3333 x the volume of the tank. This is the number that P.R. Escobal came up with as a the optimum flow-through/throughput for a protein skimmer. This is providing the protein skimmer is properly sized for the aquarium. That same number 1.3333 x is also correct for UV sterilizers according to Escobal and according to me, the right flow for a refugium. Unlike Escobal, I don't have any fancy mathematical formulas to prove that, but the consensus in the community is "low flow".
A more accurate method for determining return pump size is to match it to the protein skimmer input pump or gravity feed rate if your skimmer is fed directly by the display tank drain. If your protein skimmer processes 500 GPH, as most do, then that is your target number for the return pump. Any more will allow water to pass through the sump unfiltered, any less will diminish the efficiency of the protein skimmer as it process the deficit twice. For example, if your return pump moves 400 GPH, then 100 GPH will be processed twice before returning to the display tank. If your return pump moves 600 GPH, then 100 GPH will bypass the protein skimmer.
You should plumb your skimmer so all of the water entering the sump must go through it before moving on to the next section. This can be achieved by directing your protein skimmer effluent/out line so it delivers the processed water over a glass partition. This way all incoming water is processed and done so only once. If your return pump is stronger than your skimmer pump you will lose the difference in bypass as water overflows over the glass partition without going through the skimmer to do so. If your return pump is weaker you will process the difference twice as the processed water migrates backwards into the first (protein skimmer) section of the sump, flowing the reverse direction over the glass partition.
Some protein skimmer designs like Becketts require very high flow (often 10 x the volume of the display tank). In this case the pump will move well over the magic number of 1.3333 x the volume of the tank. For these applications, the UV sterilizer, refugium, and media reactors all need to be on a bypass.
mr.wilson
.Registered Member
The best powerhead configuration in my opinion is to position one or two at the top of one end panel facing the opposing end where the overflow box is (hopefully). Then position one or two powerheads as close to the bottom as you can get without disturbing the sand too much, at the opposing end (below the overflow box). This will give you that barrel role or circular flow. It's about as close to a gyre or laminar flow that you can get with powerheads. Unlike a closed loop, powerheads must suck and blow from the same end so a true gyre is impossible. The benefit of having half of the powerheads at the surface is you get more ripples and subsequent shimmer effect with the lighting.
With this kind of flow dynamic, it would be wise to setup your sump return line(s) to enter at the end where the overflow box and where the powerheads are near the bottom. Point the return line(s) straight down a few inches below the surface to continue the circular flow dynamic. The water coming from the sump will get picked up by the lower powerheads and get shot across the bottom of the tank. The water takes the longest trip possible before returning to the sump to be filtered again.
Some powerheads have a surge pattern whereby the pump cycles on and off in short bursts continually. If you can get the powerheads at the opposite end to run on a reverse cycle, and you time it right, the powerheads can catch a wave and continue it. Vortechs have a communication system, but unfortunately they are programmed to cycle on and off at the same time instead of a preferred staggered pattern.
Aiming powerheads directly at the rock structure will accumulate detritus as it forces particles (POC) into the rocks. Moving water from the bottom to the surface is the most efficient flow for gas exchange and climate control, but this is a challenge for most powerheads. Burying powerheads in rockwork makes it difficult to service the impellers and keep the intakes clean. Chaotic flow has some benefits, as it encourages corals to grow in all directions due to even food dispersion, but chaotic eventually forms a pattern and detritus finds dead spots to settle in. Chaotic flow also creates resistance/friction that diminishes opposing flow.
Laminar flow (gyre) creates momentum and kinetic energy/inertia. The whole idea of moving water in one direction, be it circular or linear, is the wave of the future (pun intended). Think of it like can be putting your hand in a bucket of water and quickly mixing the water clockwise (or counter) for 5 seconds. When you stop, the water continues to travel in a circular motion for quite some time. There is minimal friction loss as the flow doesn't crash into obstacles such as opposing flow, rock structures, or viewing panels.
In some cases there is a benefit to extending the intake of the powerhead to the bottom of the tank, assuming it os mounted at or near the top. This simple pipe will draw (less oxygenated) water from the bottom and deliver it to the top where the air/water interface can oxygenated it and off-gas nitrogen and Co2. The intake extension also creates a passive circular flow as water is propelled across the surface and drops down to be sucked up again. I find that powerhead intake screens are undersized in length, diameter and holes size so they plug quickly and restrict flow. A weekly scrub with a toothbrush will rectify this, but access can be difficult. Adding a larger intake screen at the bottom of an extension pipe or simply drilling holes in the pipe will spread out the suction and minimize the need to service the intakes.
mr.wilson
.Registered Member
Another quick point about protein skimmer flow-through/throughput rates; manufacturers have a limited number of base motors to use in their skimmer pump design. One of the current leading powerplants is the Sicce PSK 2500, which moves 660 GPH when used as a needlewheel skimmer pump. The other popular motor is the Askoll 1500, which moves 500 GPH when used as a needlewheel pump.
You will see these same pumps used by many manufacturers for skimmers rated for 100 - 500 gallon tanks. The truth is, it's cheaper to use an oversized pump than to engineer and custom build a smaller (right-sized) pump. It's also cheaper to use one pump to feed the skimmer water and simultaneously generate bubbles. De to these shortcuts, you will find that some manufacturers break the rule of 1.3333 x the volume of the display tank flow through/water feed rate.
A one pump (jack of all trades, master of none) skimmer is not as efficient as closed loop skimmer that uses one higher volume pump to generate bubbles and a siphon & gravity drain from the tank to feed water through it. This kind of system assures a 1.3333 feed rate and full control of bubble production without interfering with the feed.
You will see these same pumps used by many manufacturers for skimmers rated for 100 - 500 gallon tanks. The truth is, it's cheaper to use an oversized pump than to engineer and custom build a smaller (right-sized) pump. It's also cheaper to use one pump to feed the skimmer water and simultaneously generate bubbles. De to these shortcuts, you will find that some manufacturers break the rule of 1.3333 x the volume of the display tank flow through/water feed rate.
A one pump (jack of all trades, master of none) skimmer is not as efficient as closed loop skimmer that uses one higher volume pump to generate bubbles and a siphon & gravity drain from the tank to feed water through it. This kind of system assures a 1.3333 feed rate and full control of bubble production without interfering with the feed.
Can you show us some pic of this?? Becasue I have troubles with small fishes constantly going to the overflow
mr.wilson
.Registered Member
You are correct.
It's hard to find and believe water flow rates for skimmer pumps. The Sicce 2500 gets its name from the 2500 LPH, or 660 GPH, flow it produces as a water pump. I don't know if they really take the huge reduction in water movement from drawing in air into consideration. The more air you suck in, the less water you move, and the hotter the impeller/needlewheel gets. These pumps have a range of 1000 - 2400 LPH air draw depending on your needs and how hard you want to push them. Bubble size and subsequent stability is also variable along the curve. I can't find real numbers but the actual water movement is likely 200 - 400 GPH? For whatever reason, all of the ads for Sicce PSK 2500 needlewheel pumps claim it moves 660 GPH water.
The Askoll/Laguna 1500 pushes... you guessed it, 1500 GPH, or 5678 LPH. I found a few resources that claim 450 - 500 GPH of actual water movement when it is run as a needlewheel pump, but these are likely to be estimations. Royal Exclusive claims that their Red Dragon Askoll 1500 draws 1000 LPH air and moves 2000 LPH (528 GPH) water. I have also heard reports of up to 3400 LPH air draw with the Askoll 1500 using a threadwheel/meshwheel. There's no way you can add that much air (displacement) and still move 500 GPH water.
The protein skimmer market wants to hear about air draw, and to a lesser extent energy consumption, and nothing else. It's like focusing on horsepower instead of torque. As the saying goes "torque wins races, horsepower sells cars". In our case torque = contact time, bombardment (air against water), and bubble size (the smaller the better, more surface area and stability). The horsepower in the skimmer trade is air draw. Throw a $10.00 Dwyer RMA22 air flow meter on it and measure your "efficiency".
There are many ways of fine tuning efficiency. Having a smooth transition as the foam rises up the neck decreases premature bubble merging and popping, such as experienced with a cone or partial cone skimmer. Right-sizing the neck is also important. If the neck is too wide the bubbles can't climb and pop before reaching the top, releasing their protein catch. If the neck is too narrow, the bubbles merge as they are over-concentrated and jammed together.
Having the water flow one direction while the bubbles flow another (countercurrent) is a lost art of bombardment. These days a single pump system moves water and air together in one direction. Having a slightly higher salinity (1.025 instead of 1.023 or 1.024) will help you skim more. Some people draw the air for their skimmer from a drier, cooler source away from the aquarium, but often this restricts air intake due to friction loss. Ozonizers without air driers or air pump feeds (venturi intake to skimmer only) also restrict air intake volume.
The other largely overlooked issue is feeding the skimmer. The water leaving (draining from) the display should go directly to the protein skimmer, do not pass go, do not collect $200. This will assure that the "stuff" you have just skimmed from the surface of the tank continues to get "skimmed". It also makes sure detritus (particles) don't settle in the first compartment so the protein skimmer gets a fair shot at removing it. As I mentioned earlier, you need a "first in, first out" (FIFO) system (Peter should know about this from the software biz). The water that enters the skimmer first should leave first so all of the water is processed for the same (maximum) amount of (contact/dwell) time. If you set up the skimmer effluent (out) to send the processed water downstream to the next compartment in the sump, it allows the skimmer to draw new unprocessed water in without losing the FIFO order.
Too often, aquarists spend $1500 on a premium protein skimmer then use an inefficient, undersized, dual overflow box (one at each end of the tank) with teeth. Then they drop the protein skimmer randomly in the first compartment of the sump or worse, at the wrong end of the sump (last compartment before returning to the display). When you let your protein skimmer randomly suck in the same water it has just processed repeatedly, you throw all of the "efficiency" you have payed dearly for out the window. Some of that water may run through the skimmer 5 times before it is allowed to return to the aquarium, while the rest of the water bypasses it entirely. Some systems are more or less "water movers", rather than filters, simply juggling the water. A FIFO system doesn't cost a penny to set-up, and has no ill affects on the system.
- Status
Similar threads
