21 replies to this topic

[scolba]

So I have started a couple of threads mentioning this lately, but not this topic specifically yet.  I am scheming together a 265 gallon river tank based on my "home river" the Mackinaw in central Illinois.  (Link to project log here)  As much as I trust most of the folks on The Planted Tank, I think I would trust this group's knowledge on keeping native fishes a bit more. 

 

So I am settling in on a design to recreate some rheoflow (lol, I just made that word up based on rheophile) in a 7' long tank.  The rough idea is here, along with a description I wrote on TPT.

 tank plan.png   195.27KB   2 downloads

 

 

So this is some "high tech" graphics work in Microsoft Paint, so don't hold it against me. lol. What we are looking at here is the top down view on top, and then the side view below it.

The red baffle that would run most of the length, and the entire height. I didn't fill it in with solid color on the lower pic, but imagine that's an acrylic wall (or other material).

The green dotted lines on either end of the baffle would be either single or double lighting egg crate from Lowes/Home Depot. This would be for two reasons....first, to keep fish and most stuff out of the baffle area. 2nd is to help straighten the flow, so its more even. This is similar to how they control air in a wind tunnel.

I would like to put in 2 corner pieces (brown/tan) to sort of shape the flow and encourage the water turn a little bit. Maybe not necessary, but I think it will help efficiency.  Definitely optional.

The blue-gray pieces are a stand I would create to mount a pair of pumps. For pumps, in this plan, I am thinking about a pair of the Jaebo DCT series that have the speed controller. Then I would scheme up some nozzles to spread out the flow a bit, and send it down the backside of the baffle. Additionally (not pictured) I would use this space to hang the intake and outlet of a canister filter (or two).

 

So I have had a few new thoughts since writing that idea up.  First, instead of return pump style pumps, I think I am going to switch it to a recirculation style pump.  That will be a lot more cost effective.  The other thing I am considering is having the baffle slightly expand as the water flows to one side along the back...that way the water won't be really ripping when it makes that first corner, and will also help to bring up the velocity on one end, and create more of a pool like feeling on the other end.  See below for what I mean.

 tank plan - angle baffle.png   194.25KB   1 downloads

 

So  with all this in mind, my initial thought was to try and get to about 8000gph.   So breaking down into a little math....if the display area in front of the baffle on the outlet side is 16" (that's an 8" rear baffle section) and I would have 12" deep of rock and gravel for the display side (it would taper to smaller gravel and sand the further "downstream" you get) that would give an effective area of 288 sq inches, or 1.25 gal of water per 1" water column.  Going a bit further, taking 8000 gph (assuming 100% efficiency), that breaks down to 2.22 gal per sec.  So that means one point in water would move at about 1.78 inches per sec at the narrowest point.  Then as the terrain slopes down and eases, it would create less velocity on the far end.

 

So obviously this is all a rough idea.  The more obstacles from rocks and wood that's in the tank the less volume, so the faster the water will flow....but I wanted to see what you guys thought about those figures.  Are they too fast?  Too Slow?  Am I overthinking this (almost assuredly, I am...that's how I roll.  lol.) 

 

Any other thoughts or suggestions are very welcome.   I think the biggest challenge I am finding with a plan, however, is the sheer volume that's in this tank.  Some manifold type solutions just aren't feasible. 

 

Thanks a million!

Edited by scolba, 23 June 2017 - 08:50 AM.

[Cu455]

What is the purpose of the baffles? Is there a overflow or to hide the pumps? If it is to hide the pump they make pump covers that look like rocks or you can make one. This way your fish will have a little more room to swim.

 

If the tank isn't drilled and you plan on drilling it I would go with a ghost overflow on one end and the return on the other end. The water enters on one side and leaves on the other side giving it a stream like flow.

 

If you don't want a sump setup there is a thread that pops up pretty often of someone who used pvc and pumps to achieve a nice flow pattern. I am sure someone will post the link. A jebeo gyre should be fine with the flow from the filtration system. If you want you can always add a second power head if you want more movement. 

[scolba]

I appreciate the input! 

 

So the baffle is there to separate the water flow moving left to right in the back, and right to left in the front, so that the fish have a linear current.  Additionally it would be to hide the equipment, but its primary focus is separation of the current.  There isn't an overflow, and I would prefer not to drill this tank if I can help it.  Currently I have a sump and overflow on a 65 gal South American tank, and I'm not convinced it can give me a linear flow. Additionally, I'm not sure an overflow can be handle the volume that we are talking about, if my rate calculations are indeed accurate - which is a big part of this discussion.  I may be overshooting the values needed. 

 

Regarding the PVC setup, I'd wager you are referring to a river manifold setup like this one?

 image_preview.jpg   19.18KB   1 downloads

 

That is something I have considered, however when it came to finding a few powerheads to run the manifold (the type that will sit on top of a pipe), I wasn't finding any of them that were large enough to meet the assumed flow requirements.  If there is a product to consider that would get me the flow necessary for this large of a tank, I would LOVE to put a river manifold back on the table! 

 

This is another option I considered when I thought about drilling the tank.  Kind of like a river manifold, but external.  The same louvers in green dash to smooth the flow, 9 bulkhead holes drilled on either side, and then an external system with 3 pumps to recirculate the water.  Ultimately off the table, but fun to think about none-the-less. 

 tank plan - external manifold.png   190.56KB   1 downloads

Edited by scolba, 23 June 2017 - 10:22 AM.

[Michael Wolfe]

I think your idea is great and I do think your overthinking the math. When I'm snorkeling with natives they always come up behind me... they like finding the slower water I am creating. Also I have seen lots of darters do extremely well in no flow conditions (as long as the oxygenation is maintained)

So what I am trying to say is that the fish don't really need the current. It's for you. It makes the tank look great. It makes the shiners orient and school together. It makes frozen foods dance around and look live so that picky eaters catch on. It recreated the environment that we love.

So go for your plan and if you get any decent current at all (and it sounds like you will) your setup will be great.

[Chasmodes]

I agree 100% with Michael.

 

Another way that I considered would be a baffle along the bottom of the tank, hidden by rock work like a false tank bottom with intakes at either end.  If your tank is tall and not all that wide, that might be an option too.  What kind of fish to you plan to keep?  That might also make a difference.

[Matt DeLaVega]

I think you would get very natural behavior with half or a quarter of the flow. I imagine many of the fish you choose also thrive in the smaller tributaries of the Mackinaw?

 

 I like the idea of running the baffle below substrate a lot. Has the benefit of being mostly hidden like the river manifold, but actually really move some water. Not to down the river manifold, but those multiple small pvc pipes provide a huge amount of friction. For it to be really efficient, it probably needs to be plumbed with 2 inch pvc which may be possible in a tank this size. Also a large powerhead at the end could be aided with a couple smaller ones slightly downstream or a couple maxijets either way you set it up. Sounds like a fun build.

[Doug_Dame]

In my experience ... caveat one tank ... a tank that is 24" wide can support a water racetrack flow model, WITHOUT adding any structure to the tank besides pumps to move water. 1/2/3/4 pumps, as long as they're all pointed clockwise or anticlockwise, will do the trick. I've also tried the "river manifold" approach, and think it's just inherently inefficient due to the friction in the PVC piping, which is usually small diameter.

 

In addition, with the race track flow pattern you get a natural gradation in velocity in two directions ... linearly in the direction of flow, with the max velocity being directly in front of each pump, tapering off with distance as the "water jet" spreads out ... and outside to in, with the fastest flow around the tank perimeter, and a low/net-zero flow zone down the interior centerline. 

 

If you then use a variety of substrates that are proportional to the flow ... cobble, pebbles, gravel, sand, slab rock ... you have created a lot of different niches that allow different species to find their happy spots. 

 

Also ... you can test various setups for the flow patterns and velocities NOW in your current location, before you move. You can put some small floating stuff in to see what's happening at the surface, some things that barely sink to see what happens on the bottom, and if you're lucky you might find something close enough to the density of water that it will spend time in the mid-waters. A pack of bioballs or similar filtration materials would probably work. No fish, so no issues of trying to maintain the biosystem when you move, you just have to empty the tank. You may or may not want to experiment with substrates, to make sure they'll stay where you want them to, in various velocity zones.

 

Buy 2 pumps. Try them in various configurations. If you want more velocity in some places, add another. Etc. You're going to have to buy pumps anyway, so financially there's no significant difference between starting now vs starting after you're in the new house. But you might save money by testing incrementally, and avoiding buying more or bigger pumps than you find you really need. Although with fishless testing, you're not going to know which of the zones you're creating will be most attractive to the various kinds of Mackinaw fish you want to keep.

 

In the waterways in which I've collected, most of the fish I've caught/seen have NOT been in the maximum velocity zones. (There may be some sampling bias in that, it's easier to catch fish in the slower/shallower areas. Especially for an old geezer like me.) 

 

===> Todd Crail wrote a fabulous article for American Currents (the NANFA journal) some years ago, entitled "System Design for the Ultimate Native Fish Aquarium," in which he very nicely describes designing a tank to maximize the number of different micro-habitats. It's a must-read if you're planning a big tank for a mixed community of fishes. (Vol 32, No.2)

 

HTH

[Josh Blaylock]

I agree with MW too.  In my 125, the shiner actively try to get out of the current.  They typically like it when I shut off the current pump, and occupy that high flow space.  Because only about 1/2 of my tank has a lot of flow, the shiners typically congregate in the slower moving section.

 

I have the river manifold in my 75gal, and I really like that setup.  It's cheap and easy to make.  If I had to break down my 125 for some reason, I would use the manifold instead of the internal water pump..

[Michael Wolfe]

If you then use a variety of substrates that are proportional to the flow ... cobble, pebbles, gravel, sand, slab rock ... you have created a lot of different niches that allow different species to find their happy spots. 

 

Also ... you can test various setups for the flow patterns and velocities NOW in your current location, before you move. You can put some small floating stuff in to see what's happening at the surface, some things that barely sink to see what happens on the bottom, and if you're lucky you might find something close enough to the density of water that it will spend time in the mid-waters. A pack of bioballs or similar filtration materials would probably work. No fish, so no issues of trying to maintain the biosystem when you move, you just have to empty the tank. You may or may not want to experiment with substrates, to make sure they'll stay where you want them to, in various velocity zones.

 

Buy 2 pumps. Try them in various configurations. If you want more velocity in some places, add another. Etc. You're going to have to buy pumps anyway, so financially there's no significant difference between starting now vs starting after you're in the new house. But you might save money by testing incrementally, and avoiding buying more or bigger pumps than you find you really need. Although with fishless testing, you're not going to know which of the zones you're creating will be most attractive to the various kinds of Mackinaw fish you want to keep.

 

HTH

 

 hmmm, wise is this one in the way of the flow... 

 

really good point about substrate... dont think that you get to lay out a tank just the way you want... fish help... and flow of the type you are talking about changes things a lot... we learned that lesson (happily without real problem) on the Autrey Mill 125... it becomes a constant surprise what you might see... just go with the flow.

[scolba]

Haha doesn't that figure...I hop in the truck to make a 9 hour road trip (picking up our new boat, woo!!!) and the thread takes off! Thank you guys so much for the input! I have additional questions and clarifications, but won't be able to really give it some time until later this weekend. But I can say already this is why I asked here! You guys have such great perspectives, and I really appreciate you taking the time to reply with well thought out answers!!!

Sent from my SAMSUNG-SM-G891A using Tapatalk

Edited by scolba, 24 June 2017 - 09:20 AM.

[gerald]

Part of the reason fish spend time in flowing water, in runs or head of pool just below a riffle, is to catch benthic insects that drift off the riffle (especially when large mammals have just walked across the riffle!).  Riffles are where much of the fish-food production occurs in streams and small-med size rivers.  In aquaria, fish that were strongly rheophilic in nature soon learn that strong currents in aquaria do not yield the same food rewards.  They may prefer to spend most of their time NOT swimming against the current.

[Michael Wolfe]

Part of the reason fish spend time in flowing water, in runs or head of pool just below a riffle, is to catch benthic insects that drift off the riffle (especially when large mammals have just walked across the riffle!).  Riffles are where much of the fish-food production occurs in streams and small-med size rivers.  In aquaria, fish that were strongly rheophilic in nature soon learn that strong currents in aquaria do not yield the same food rewards.  They may prefer to spend most of their time NOT swimming against the current.

 

this, this, this... plus he worked in "rheophilic"!

[scolba]

I think your idea is great and I do think your overthinking the math. When I'm snorkeling with natives they always come up behind me... they like finding the slower water I am creating. Also I have seen lots of darters do extremely well in no flow conditions (as long as the oxygenation is maintained)

So what I am trying to say is that the fish don't really need the current. It's for you. It makes the tank look great. It makes the shiners orient and school together. It makes frozen foods dance around and look live so that picky eaters catch on. It recreated the environment that we love.

So go for your plan and if you get any decent current at all (and it sounds like you will) your setup will be great.

 

Haha, I'm glad you said I was overthinking...its truly a problem I have.   

 

Very intriguing take on the current (in a tank, anyway) being for the cool factor.  I guess I always assumed that if fish lived in current, they had to have it, rather than living there despite it.  Good stuff. 

 

I agree 100% with Michael.

 

Another way that I considered would be a baffle along the bottom of the tank, hidden by rock work like a false tank bottom with intakes at either end.  If your tank is tall and not all that wide, that might be an option too.  What kind of fish to you plan to keep?  That might also make a difference.

 

Wow, this has giving me some ideas!!  It really is like a manifold, but with efficiency!  Man, this would be perfect for my tank, too.  Its 84x24x30.  I wasn't super thrilled with the 30" height, and wasn't thrilled with the race track taking up width.  As for fish, this would be my target list, with darters and red shiners the most desired (thank you @BenCantrell for narrowing it down!):

1. southern redbelly dace
2. red shiner
3. spotfin shiner
4. steelcolor shiner
5. redfin shiner
6. western blacknose dace
7. suckermouth minnow
8. central stoneroller
9. blackstripe topminnow
10. orangespotted sunfish
11. rainbow darter
12. orangethroat darter
13. logperch
14. slenderhead darter
15. blackside darter

I'm not saying I will keep all, but these would be ones, that if netted, I would be interested in.

 

I think you would get very natural behavior with half or a quarter of the flow. I imagine many of the fish you choose also thrive in the smaller tributaries of the Mackinaw?

 

 I like the idea of running the baffle below substrate a lot. Has the benefit of being mostly hidden like the river manifold, but actually really move some water. Not to down the river manifold, but those multiple small pvc pipes provide a huge amount of friction. For it to be really efficient, it probably needs to be plumbed with 2 inch pvc which may be possible in a tank this size. Also a large powerhead at the end could be aided with a couple smaller ones slightly downstream or a couple maxijets either way you set it up. Sounds like a fun build.

 

half or quarter my initial estimate seems a lot more doable.    But yeah, you and I feel similarly about the actual manifold setup.  One of the biggest issues for me, aside from flow, of the manifold setup is visible pumps.  For whatever reason, I am just not a fan. 

[scolba]

In my experience ... caveat one tank ... a tank that is 24" wide can support a water racetrack flow model, WITHOUT adding any structure to the tank besides pumps to move water. 1/2/3/4 pumps, as long as they're all pointed clockwise or anticlockwise, will do the trick. I've also tried the "river manifold" approach, and think it's just inherently inefficient due to the friction in the PVC piping, which is usually small diameter.

 

In addition, with the race track flow pattern you get a natural gradation in velocity in two directions ... linearly in the direction of flow, with the max velocity being directly in front of each pump, tapering off with distance as the "water jet" spreads out ... and outside to in, with the fastest flow around the tank perimeter, and a low/net-zero flow zone down the interior centerline. 

 

If you then use a variety of substrates that are proportional to the flow ... cobble, pebbles, gravel, sand, slab rock ... you have created a lot of different niches that allow different species to find their happy spots. 

 

Also ... you can test various setups for the flow patterns and velocities NOW in your current location, before you move. You can put some small floating stuff in to see what's happening at the surface, some things that barely sink to see what happens on the bottom, and if you're lucky you might find something close enough to the density of water that it will spend time in the mid-waters. A pack of bioballs or similar filtration materials would probably work. No fish, so no issues of trying to maintain the biosystem when you move, you just have to empty the tank. You may or may not want to experiment with substrates, to make sure they'll stay where you want them to, in various velocity zones.

 

Buy 2 pumps. Try them in various configurations. If you want more velocity in some places, add another. Etc. You're going to have to buy pumps anyway, so financially there's no significant difference between starting now vs starting after you're in the new house. But you might save money by testing incrementally, and avoiding buying more or bigger pumps than you find you really need. Although with fishless testing, you're not going to know which of the zones you're creating will be most attractive to the various kinds of Mackinaw fish you want to keep.

 

In the waterways in which I've collected, most of the fish I've caught/seen have NOT been in the maximum velocity zones. (There may be some sampling bias in that, it's easier to catch fish in the slower/shallower areas. Especially for an old geezer like me.) 

 

===> Todd Crail wrote a fabulous article for American Currents (the NANFA journal) some years ago, entitled "System Design for the Ultimate Native Fish Aquarium," in which he very nicely describes designing a tank to maximize the number of different micro-habitats. It's a must-read if you're planning a big tank for a mixed community of fishes. (Vol 32, No.2)

 

HTH

 

haha, I don't think you have a sampling bias.  Of all the years I spent fishing, the only time I have caught anything in a current is when the bait was drug by a big rock, and a fish hanging in the slack pounced on it.  So what you say makes a ton of sense!  Great information!! 

 

Regarding your baffleless racetrack....that is something I had considered...and putting dw or rocks in the center as sort of a natural barrier to help out...but I think its what MW said....the linear flow looks cool for ME.    I might have to stick with some complicated setup because it appeals to me, but I really appreciate your input.  The wife may eventually overrule me and decree your idea when, in a couple of months, I am frozen with indecision and can't move forward.  lol

 

I'll seek out that article, too!  thank you!

[scolba]

 

 hmmm, wise is this one in the way of the flow... 

 

really good point about substrate... dont think that you get to lay out a tank just the way you want... fish help... and flow of the type you are talking about changes things a lot... we learned that lesson (happily without real problem) on the Autrey Mill 125... it becomes a constant surprise what you might see... just go with the flow.

 

That's a good state of mind to take on regarding the substrate and plan in general.  Kind of reminds me of the old saying....No plan survives contact with the enemy.  Lol, maybe a bit dramatic for these purposes, but it does fit.  Really though, hydrodynamics have fascinated me, ever since I was a kid.  So a higher flow tank just took on an additional bit of cool.  Watching the materials shift. 

 

 

Part of the reason fish spend time in flowing water, in runs or head of pool just below a riffle, is to catch benthic insects that drift off the riffle (especially when large mammals have just walked across the riffle!).  Riffles are where much of the fish-food production occurs in streams and small-med size rivers.  In aquaria, fish that were strongly rheophilic in nature soon learn that strong currents in aquaria do not yield the same food rewards.  They may prefer to spend most of their time NOT swimming against the current.

 

This.....blew....my....mind.  Such a fascinating factor to consider.  Even if there wasn't a ton of other good info in this thread, that information alone could bring me back from the bleeding edge of flow. 

 

 

 

this, this, this... plus he worked in "rheophilic"!

 

lol, YES! 

[littlen]

I'll add weight to the statement that given a choice of high flow vs. low(er) flow, you'll find that the fish will tend to stay in the slower areas.  Also, I have a 150 and I believe it is 28" tall, which is not all utilized.  18-20" would be plenty.  I initially started off with tons of flow, but cut back on a few pumps as they really just weren't necessary.  1, they added extra heat to a system I was trying to cool [with a chiller].  2, the fish stayed in the slower flow areas.  I have lots of large/tall rocks and driftwood that really impacts the flow.  If/when I start over I may try the manifold setup, and must less tank decor.

[scolba]

Ok, so here is my take on what im calling an open manifold.  "Manifold" still seems like an appropriate term, but this one obviously doesn't have the same restrictions....so open.

 

Anyhoo...now with decorations too!  Haha.  Just a rough thought about how i would arrange it.  Big/small rocks initially, then DW, then a few more rocks, then plants.  Note the uneven height on the ends of the baffle to help hold substrate material.  Addiotnally the green is the egg crate material to help keep big things out of the bottom area.  Also, I added a couple of braces under the main baffle, since its going to be supporting a lot of work.  IN the upper part of the pic its looking down at them, they are gray with a red outline on the lower pic.

 

So some challenges with this approach....how to place and use pumps or recirculation pumps.  I just put in a few of the recirc deals for illustration purposes...but getting access to those could be interesting.  Any suggestions there? 

 

But I tell ya, that challenge aside, I really like this approach.  Its certainly not one you would see a lot of. 

 

 tank plan - open manifold.png   232.91KB   1 downloads

[Michael Wolfe]

 

 

1. southern redbelly dace
2. red shiner
3. spotfin shiner
4. steelcolor shiner
5. redfin shiner
6. western blacknose dace
7. suckermouth minnow
8. central stoneroller
9. blackstripe topminnow
10. orangespotted sunfish
11. rainbow darter
12. orangethroat darter
13. logperch
14. slenderhead darter
15. blackside darter

 

 

That's a good community fish list as far as I am concerned.  You are really only missing my favorite to make it perfect... you need the Nocomis!  You know you have one up there... and everyone likes big fish... and they are pretty good at not eating the smaller fish...

[scolba]

Looks like the horneyhead chub was the only nocomis to be collected in some of the surveys. Cool looking...like the darth maul of chubs. Lol

Edited by scolba, 27 June 2017 - 08:11 PM.

[Chasmodes]

I like the design but I would find a way to make to easy to access your pumps for repairs and maintenance.  You can always use hardscaping materials to hide them and the egg crate.  It seems like the pump on the right is pumping directly into the right side tank wall and I'm not sure you'd get the directional flow that you were looking for.  Maybe consider the pump on the right being outside the baffle, pumping the water to the left, but hidden by rocks and such.  Get flow like this:

 

 

                                                                               <--

     _____________________________________

-->

 

I've never tried anything like this but have thought about it a lot.  I have a 75g tank, so not really a lot of room to work with something like this. I decided instead to go with a strong powerhead to achieve flow from the left to right of my tank.  I'm hiding it within and artificial root structure.  I'll definitely be following your build though.  It will be interesting to see what you come up with.  Good luck!