MMcDonald 285 gallon Plywood Build Thread

Sounds good. Gotta keep the wifey happy

 

The topic for today is flow.... after reading much... I concluded gyre flow and focusing on mass water movement and momentum makes much more sense than turnover rate. Very interesting reads. It also makes more sense to avoid dead spots in the tank.

Given all of that, here are my thoughts for the group to debate and correct....

1) Overflow/Return Loop.... Island of live rock in the middle of the tank front to back and most of the length of the tank. Coming up though the LR will be a center overflow. Also coming up from from the center will be the return flow. The return will pump into the rock stack causing random flow coming out of the island of LR itself as the flow bounces off the rocks. This flow will also minimize detrius from accumulating in the LR island itself. In the pictures, red/pink lines are input/return flow and light blue are overflow/output lines. So... center overflow, return pumped into LR island stack. 1000 GPH pump on the return, but it also will drive GC/GFO my reactors. (Plus I already have it.)

2) Gyre flow.... the point of gyre is to get mass water movement going clockwise and then reversing to counter clockwise. You can do horizontal or vertical dividers, I chose to use my LR island as a vertical divider and rotate the water around it. To get the water moving, I have a closed loop system planned. One red supply line and one blue return line will be operating at a time. For example, the red on the left and the blue on the right together to get the water being pushed (input) along the back of the tank and pulled (output) along the front of the tank. On the opposite wall of the tank, the opposite will be occuring, the back wall pulling and front wall pushing. This would establish a clockwise flow around the tank. Every 5-10 minutes, versus the direction of the flow to counter clockwise. Get something like a 4000 GHP pump for the closed loop system.

From a turn over point of view, I'd be at 5000GPH for 254 net total system volume.... roughly 20 times. From a gyre point of view, I am establishing clockwise and counter clockwise flow....

Here is the picture link

Inputs and thoughts appreciated as always.

Mark

 

bump ... any thoughts on this flow design??

M

 

You have me interested in the Gyre flow concept - any links to schemas or pics of actual systems that you can share Mark?

 

Gyre Flow Link

Here is a link that is part of a 5 part discussion on flow.... scientifically based. Be prepared for a technical read. Really makes a lot of sense when you look at the data.

Interested in your thoughts. It seems like a 'fundamental" that is possibly being commonly mishandled. I have actually tried to contact one of the researchers directly. We'll see if he responds.

Mark

 

Coincidental timing... just got a call back... one of the researchers in the article made an appointment to call me tomorrow. Very cool.

Mark

 

The gyre effect sounds good. I don't see anything wrong with it, but more traditional flow methods can be used.

 

Thought about the possibilities. It would be easy to do one direction, reversing gets tricky. I don't see how to do it woithout the selenoids. Tried thinking how I would do it from the ends of a long tank. MP40 would be good, but to reverse you would need two sets. Either way gets pretty pricey. 4 MP40s or two loops with two selenoids. Problem is though I was thinking of a *****ula bulid with the overflow on the end. Really complicates things. Moving a lot of water close to the sand I'm not sure of.... lots of stuff to work out for a complcated way of doing things.

My only thought would be that it would be easy to get a mass movement, but it would be trick to keep enough flow through the rocks. Most my rocks are off the sand, so to put the returns under the rocks would be good.... but then I have to rely on check valves... not very reassuring to think of draining the whole tank. Doing a center overflow like you want is a real good plan.

Let us know how that coversation goes.

 

Agree with what you said Powerman, you'll notice I went with a center overflow. Also definitely need solenoids to switch directions.... or two pumps on timers.....

Looking forward to talking to this guy.... I'll post a summary of the conversation....

For flow through the rocks, I am putting my sump return plumbed in the rock island internal structure so there will be flow iminating from inside the rock out and encircling it with the gyre.

M

 

Hi Mark - I read the Gyre Flow article just now. That was very interesting and makes me look at my tank a bit differently. I agree with premise that our understanding of flow must catch up to our understanding of lighting, particularly with moving a mass of water rather than shooting it with 'squirt guns' as Jake said. That article is a nice intro, but it makes me crave solutions to moving the water mass.

A solution that doesn't include a horizontal divider going across the center of the tank. That might work for frag tanks - but would be rather odd in a display tank. So I would pose, how would you do this and not lose a lot of aesthetic points for presentation? I couldn't quite make out how the vertical method works/looks. Perhaps that is better for a display tank.

Not sure how far you have gone with your research, but if you haven't you might want to look into surge devices. Not a carlson dump bucket per se, but I do recall one particular one years back that I thought was rather well done. I wish I could recall all the details but it involved the surge happening while hidden behind the back wall - in other words, the aquarium actually continued behind the back wall and the surge was created back there and released into the aquarium.

Perhaps some combination of old design, with this new look at flow could create something successful.

Back to the article, I enjoyed that and it made me feel better about my new tank. I had already set the pump controller at the longest interval and only have one pump in the tank that causes the water flow to gyre counter-clockwise.

I think ultimately the challenge will be to balance flow needs to the aesthetic requirements of your display tank.