New 360Gallon sump & circulation design

[uncleof6]

uncle - good point on keeping the two sumps at different levels to help the gravity flow. My original idea was to stack them but was concerned with the height of the first sump being too close to the bottom of the show tank. Maybe an intermediate solution with the first sump about a foot higher than the second is a reasonable compromise. That would yield about 4800 gph.

But again this is "theoretical" not real world. The figures do not account for friction loss in the plumbing--the pipe itself, fittings etc as i stated in previous post (add friction loss) and bean stated earlier today in another thread.

Using check valves is a habit I picked up a long time ago. I don't like the idea of dropping the top 2" of water in my main tank if I turn off main return pump. I would sometimes stack live rock and sps close enough to the surface that dropping 2" would be a problem. Not full exposure, but would only give me 1" of water over the corals with MH beating down.

Will leave this one alone. Other than to state piling rock up that high I believe to be counter productive in terms of flow quality in the tank.

 

[uncleof6]

so on another point.. what is a reasonable cycle flow rate for a 360 gallon show tank? I was thinking of something like 7000 gph?

360g - overflow (60g) - sand & rocks (100g?) = 200g

200g x 35turns/hr = 7000gph

Can't find my old Julian Sprung book, so working off of memory again...

Before commenting on your question I need to clear up a "brain cloud"....

"Even at your desired flow rate of 1800 gph for the 1 tank, let alone the flow from the other tanks, running on the same pump--"

This comment is out of place, and actually refers to another system in another thread. OOPS..... but the point I was making is valid.

Main flow 10x the total system volume, and according to arbitrary "rules of thumb" that basically have no meaning anywhere from 20x to 100x system volume total flow.........note that these rates apply to total system volume, just as everything else in aquarium science--not the display tank running volume. This includes the water in the plumbing, sumps, reactors, skimmer--all the water.

What is more important, is the quality of the circulation in the tank, aside from the main pump, than the actual number associated with this circulation. I will reiterate, that the surge system you are planning, is not going to provide the quality of flow needed as it will leave many dead areas (no flow) in that large tank--it is a visual effect, not a flow scheme. Power heads, despite your distaste for the distraction, are the solution. Function trumps aesthetics.

 

[karimwassef]

Your opinion on surge devices' futility is noted.

Having reef diving experience and comparing it to the motion of water in tanks with and without surge, I have a different opinion. Unless you have a technical publication that identifies that random surge-induced water motion is counter-productive, repeating opposing opinions doesn't add much to the discussion.

 

[karimwassef]

The brain cloud must refer to the fact that my question was not well understood... let me try again.

The main tank is not a sufficient filter for the water (live rock and sand noted). Good water flow in the main tank is absolutely critical, but that is not my question.

Specifically, my protein skimmer, DSB, chiller and calcium reactor are only engaged in the circulation through the sump. The most critical are the protein skimmer and DSB - so water that does not flow through the sump does not get skimmed or move nutrients from the main tank to the DSB. I also consider a protein skimmer to be essential in the oxygenation of the water.

So, specifically - how frequently should the water in my tank circulate through the "filter"?

 

[uncleof6]

The brain cloud was I was typing in one thread and thinking about things in another thread.

 

[karimwassef]

That statement was confusing and brain cloud worthy.

Following the total tank math:

200g + 120g sump + 30g other ~ 350g (approx)

At 20x, that's 7000 gph minimum.

Is that about right?

 

[Lavoisier]

Your opinion on surge devices' futility is noted.

Having reef diving experience and comparing it to the motion of water in tanks with and without surge, I have a different opinion. Unless you have a technical publication that identifies that random surge-induced water motion is counter-productive, repeating opposing opinions doesn't add much to the discussion.

Karim,

Your comment is helpful to me. I, too have had the pleasure of diving on a reef (Florida Keys and Tabago) and a surge device allows for a degree of "randomness" I have found on a reef which I do not find with the less expensive technology such as a wave box--it is to "regular."

I do own a (1) MP40 which I use on my 180 but to achieve an observable random surge I am convinced I would need two and simply cannot afford the expense at this point.

On my 90g I have achieved that observable random surge with a 5g carlson surge device (never experienced any failures over several years) and I can imagine the increased randomness with several (two to four maybe 10g or even 20g in a 4ftx8ft 600g DT which I am building) buckets dumping at various times. I believe I could achieve a similar effect with 2 MP60s but the $1500 to do so is daunting to me (I teach HS for a living and my disposable income is limited!).

I am not convinced at this point that this issue is purely aesthetic, though certainly beauty is a large part of the "end" (not "result") I seek, but I will use inexpensive (both to purchase and run) Korelia magnum 8s to insure water flow until I see some empirical evidence that my surge devices can suffice for superior water movement. Like you, I would pull my powerheads in a aesthetic heartbeat if I was convinced I did not need them!

Sorry for the long, rambling post. I am interested in your reflections when you have the time to respond.

Kind Regards,

Laviosier

 

[karimwassef]

Lavoisier - I think it's not an "either-or", but an "and". I've always preferred a lot of sump return flow vs. powerhead flow due to the aesthetics, but the surge is a completely different flow pattern. I would do both surge and non-surge.

I also tend to work on a budget (part of the reason for the DIY), and the expense of the high volume powerheads is extreme in my opinion. The same goes for DIY LEDs vs. commercial units. The in-tank pumps are a luxury item without the aesthetics - so it's a personal choice. If you like them, enjoy them.

There are three kinds of flows that I see in a tank - laminar, turbulent, and surge (not really a type of flow, but you'll see my point). They oxygenate and avoid dead zones. Laminar flow is smooth and streamlined undisrupted flow without eddies. Turbulent flow is random, rough and forms eddies. Both are needed.

Surge is more a matter of volume and time. It can be laminar or turbulent, but my intent is to use cross current surges that are intentionally at slightly different periods to create a relatively (but not really) random flow similar to what I experience when diving. Sometimes they will add (surge at the same time) to create an intensely turbulent zone for a few seconds and sometimes they will be completely out of phase (surge at opposite times) to create a pull and push flow.

There's also diffuser plates and flow reflectors to add to the fun. It's more an art than a science and my intent is to avoid stagnant or slow moving water in the main tank without ending up with sand mountains and valleys.

just my thoughts

 

[karimwassef]

Here's a view of how I'd like it to work. Red is surge 1 and blue is surge 2

<a href="http://s1062.beta.photobucket.com/user/karimwassef/library/" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/01716ca1.jpg" border="0" alt="Photobucket"/></a>

 

[Lavoisier]

Yes, nice simulation of some random flows.

 

[Lavoisier]

A better term than "random" might be "complex."

 

[karimwassef]

taking all the feedback, here is the updated circulation flow

<a href="http://s1062.beta.photobucket.com/user/karimwassef/library/" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/e53234d9.jpg" border="0" alt="Photobucket"/></a>

and the in-tank flow

<a href="http://s1062.beta.photobucket.com/user/karimwassef/library/" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/a23da829.jpg" border="0" alt="Photobucket"/></a>

any concerns?

 

[Lavoisier]

I had never really looked at the "numbers" on my 5g carlson so I timed the flow. I am assuming from something you said that the 5g actually only siphons 3g. (the device is up against the bottom of the floor between 16"oc joists, so observing a more accurate number is to much trouble!):

60 sec/cycle +/- 4sec
3 sec for 3g dump

The 60sec cycle includes 10 sec of no water flow, 45 sec of slowly increasing flow, and 3 sec of full siphon flow.

So roughly (very) the device moves water at its 3sec peak at 3600gph and in between peaks the water is flowing at a steadily increasing rate.

I don't know the volume of water as I run this on a Blue Line 30 but it feeds a refugium and I adjust a single return to the DST to create the above cycle. The drop from the top of the siphon is somewhere between 24" to 30" (I built the device so long ago that I cannot remember how high up the bucket I came) with a 2" return and no reducers.

I have several questions I hope someone can help me with. I am a language not a math guy so the physics have to be explained to me carefully and slowly!!...or send me to a site or source for laymen.

1. What is the most efficient way to increase the peak gph for a carlson device? Increase pipe diameter and use reducers? Height of drop? (limited for me to somewhere between 30-36in as this new build will be in the basement).

2. Given other variables being equal what will the difference between container sizes--5g, 10g, or 20g--be (other than the time it takes to fill larger containers) in the surge? Duration? Rate? Volume?

 

[karimwassef]

The flow rate is a function of the difference in water level and the diameter of the pipe. Beananimal's website (linked before) has a calculator where you enter the two parameters and you can see the gph as the result. Using a reducer at the very end will increase the speed immediately at the nozzle, but would reduce the total flow rate.

Any kinks and corners also increase resistance and reduce total flow.

A secondary effect is the pipe diameter's resistance to flow. This is usually negligible for very short distances unless the pipe is very small. It could play a role if you have a long pipe. A tertiary effect would be turbulence in the pipe if it is too large. In this case, I doubt either has much impact.

Since the surge tank water level changes (as it empties), the starting and ending flow rates are different. Increasing the tank volume would have different results depending on whether you increased the tank height (water level) or base area.

If you increase height, the increase the starting flow rate. Just increasing the volume (either way) would increase the duration of the surge and the refill time.

Hope that helps.

 

[karimwassef]

http://www.lmnoeng.com/Tank/TankTime.htm

http://www.freecalc.com/drain.htm

Enjoy

 

[Lavoisier]

Thank you, Karim--carefully and slowly explained plus sites!! Very helpful.

 

[karimwassef]

Ok. After some extensive discussions and advice (thanks to everyone who contributed), I've reworked the water circuit to include 3 resevoirs and a single 120 gallon sump with partitions. The last partition is large enough to accomodate 38 gallons down to 18 gallons in case both surges are excited at the same time (2 x 10gallons).

<a href="http://s1062.beta.photobucket.com/user/karimwassef/library/" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/reef7_zps6bf6dd74.jpg" border="0" alt="Photobucket"/></a>

I appreciate all the input to help me create a robust solution. Let me know if I've missed anything.

 

[karimwassef]

A little more on the thinking behind the build - to see if it makes sense to others:

SURGE CAPACITY and ATO:
The surge tanks are 10 gallons each. If both surge at the same time, the water level in last partition in the sump will rise by 9 inches (8 inches to 17 inches = 20 gallons). The other partitions and the main tank will rise temporarily, but only the last partition's water level would see this last. This is also the section where evaporation would change the water level. This means that the ATO sensor will be set at 8 inches, but will occasionally be submerged during surges.

WATER CHANGES:
The three resevoirs are 85 gallons each (RO/DI + ATO + new saltwater). To remove water from the system: both the skimmer feed pump and the surge fill pump have valves so that they can be used to drain the first and last partitions of the sump (leaving the sand bed underwater). Then, the saltwater change resevoir water is used to replenish both.

CALCIUM & PH:
I also added a small kalk chamber in the ATO resevoir so that when fresh RO/DI water is added, the equivalent kalk is added to this submerged chamber. The idea is to use both Kalk to increase pH and hardness as well as the calcium reactor to add calcium. I moved the ATO behind the refugium to avoid having both returns co-located in the last sump partition.

SKIMMING:
I also moved the protein skimmer return to the last partition (inlet from the first partition) to avoid having the same water recirculating in the skimmer (which is already recirculating).

Looking to validate these changes and to avoid expensive fixes later. Thanks in advance.