In-wall 380gal tank - cut out options

[Michael Hoaster]

Thanks, Karim. I'm on page 7 of your thread right now. Very impressive! I'll try not to ask questions until I finish reading it. Love the in-wall build! May try one next time.

You're right about 'lack of housing' stress. Maybe you could add some thin, false wall 'envelopes' onto your fake wall, or you could just add some live rock. Fish do seem to have an uncanny ability to find nooks.

Those Urchins taking care of business?

 

[Michael Hoaster]

OK, I've read it all. A technological tour de force! Your surge device and skimmer are just awesome! I'd love to see a new full tank shot, with all the life in there.

One thing I don't think you posted is your overall goals of this tank. Are you emulating a reef crest? Who gets priority? Corals? Fish? Are you attempting to optimize conditions for any particular species? Do you have a fish, coral, invert list? Who's the star of the show? I'd love to hear more about how you want this tank to turn out-your 'vision'.

After looking at your skimmate, I'm reminded how much fun it is to shop for skimmers, with all their shiny new parts and gizmo-lust. Then you set it up and run it, and it just gets nasty instantly! Which of course, is what it's supposed to do. Yours is the skimmer of the decade!

Oh yeah, what height did you settle on for the tank? When I designed my cabinet, I put my tank at about 36 inches hi, and I wish I'd done it lower, for seated viewing. I love to sit and stare…

 

[karimwassef]

The purpose is to grow encrusting sps topped with plating and branching sps. It's a gradual process so I'm starting with softies for now until it's more established. The fish were an afterthought for the family and to act like gardeners to keep the weeds clear.

Priority is hard coral and their growth rate.

My vision was to have a self sustaining sps tank that requires as little maintenance as possible. Food and flow are really important to me. A thick plankton environment at night and a powerful surging flow during the day to replicate the reef shelves that experience both. If I could create a low tide event to briefly expose the sps at night, I would try it.

I'm on the road so I can't measure right now but I think I ended up at 38".

 

[Michael Hoaster]

Well put, Sir! Thanks for that, and even while on the road!

You've succeeded brilliantly in providing surging flow of a reef shelf environment. I have no doubt you'll have a thriving sps tank in time. By the way, when was your start date?

I definitely get the fish thing. I just added two mollies to mine to help with algae. Looks like you have some beautiful fish, and it doesn't hurt to have the fam on board, huh?

Of course I read your fake wall thread before I began mine. If ever have to do another fake wall, God forbid, I'd go with your clothcrete method. I remember you posting how easy it was to achieve a mud like look. And of course, it doesn't float.

I like calming the tank down at night too. And low tide would be very cool. I'm sure you'll come up with something to make it happen. Maybe you could use the Apex and your surge to lower the water level.

Barstools, or some other tall seating works well with that height.

Safe travels!

 

[karimwassef]

First salt and sand was July 14th 2014. First life (cured LR frags and bacteria) was the same week. So we're around the 100 day mark.

I couldn't travel without my Apex. It keeps me calm when I start to think of "what-ifs".

The funny thing is that for the fish apartments, I'm thinking of going foam since it'll be hidden behind the rocks!

The only way to lower the level is to change the level of my end to end weir, but then I can only raise it with a plastic gate, not lower it. The alternative is to have a lower level overflow pipe that opens at night. I'd need to drill the glass or have a symphony start pump to get it started. I'd also have to actuate it electronically.

Let's call it a 2016 project.

 

[karimwassef]

Here's my third thread on the tank- chemistry.
http://www.reefcentral.com/forums/showthread.php?t=2438213&page=10

 

[karimwassef]

So. I have a new challenge. My surge is too strong coming out of a 2" PVC elbow. It creates a flow that scoops up the sand creating a small storm and moving the sand bed into hills and valleys. It looks very natural until it digs to the glass bottom in one corner.

I got the rock work and flow direction of the first surge to crash and diffuse in and around the rocks. The second outlet is proving more difficult. I even pointed it a little upwards so it flows up and across the diagonal of the whole 8' x 3' tank. But it still digs a triangle in the opposite corner.

My solution is to go from a round PVC elbow outlet to a slot in a 2' long PVC pipe. The idea is to create a sheet of flow instead of a barrel of flow.

Now the engineering question. Should I taper the slot so the larger end furthest from the inlet still gets some water? Should I try and keep the aperture area the same as the 2" round PVC ? Should I end the pipe with a reducer & elbow (say to 1") to avoid a back pressure hit when the surge hits the end of the pipe? Should I redesign with a 1" pipe and the same aperture slot?

I could also do several small Ts at 1" but that would be harder to hide in concrete. I don't think it'll look better.

I could do a slot but use plastic straws to force a laminar output?

1. PVC diameter: 2" or 1"?
2. Single slot or drilled holes?
3. Aperture area?
4. Tapered slot/holes?
5. Laminar straws or no?
6. End pipe tapered elbow or hard stop cap?

 

[Lavoisier]

First salt and sand was July 14th 2014. First life (cured LR frags and bacteria) was the same week. So we're around the 100 day mark.

I couldn't travel without my Apex. It keeps me calm when I start to think of "what-ifs".

I've set up my Apex and I can see what you mean. What an amazing tool! I'm pretty sure I'll spring for a video camera in order to add a level of emotional security during travels.:celeb2:

 

[Michael Hoaster]

Karim, you could test several of those options, using like a slip fitting, maybe combined with a hose clamp for security. Also, is it an option just to shorten the surge pipe, so the outlet sits a little higher in the tank? I'm kinda hoping for some natural sand ripples in my tank too, but as you said, that sand's gotta go somewhere!

I've heard nothing but good things about the Apex. Lavoisier, I set up a web-cam to watch a remote sump in my crawl space, a while back. It was so nice to check in without the hassle of going down there!

 

[karimwassef]

I'm going to experiment, but I wanted a starting point that's close.

Raising the surge is also problematic. The flow is so intense in speed and volume that it creates surface waves that create air tornados that can reach down to the sand bed. That creates a sand and bubble storm.

The surface wave also creates salt water splash that can reach almost a foot in the air (shy of my halides).

By the way, the corals love this stuff. It's just unpleasant for me.

 

[karimwassef]

For minutes after the surge is off, "dust devils" will form over the sand bed. These look like tiny 6" high twisters that form, wander and die down. The fish sometimes chase them.

 

[karimwassef]

By the way, I have a bubble free surge - the surge water comes in clear if deep enough. However, my overflow weir and plumbing to the sump creates some bubbles (still thinking about that). The bubbles get carried into the tank by the return pump.

That took a while to figure out. My surge flows in bubble free, but my return pump gets bubbles seconds later.

 

[Michael Hoaster]

Doing the slot for laminar flow might keep you in the sweet spot between the sand and the surface. Or one of your other ideas will do it.

Splashing and salt creep es no bueno.

How about increasing output capacity to decrease flow velocity? I'm sure you've already thought of all this stuff.

I bet the fish enjoy it as well!

 

[karimwassef]

The fish are usually surprised and shocked the first time it happens. Most of them are tank raised and have long forgotten what a wave actually feels like. They swim behind the rocks and breathe hard. If they don't swim vigorously during the surge, they'll get slammed against the rock. But then it passes and they come out to explore again. My first was the sailfin and he would practice in the wave trying to hover in position to eat the hair algae. Then he'd swim into the wave like it was a rival with his fins raised full tilt. Eventually, he got the hang of it on his own. Sometimes he'd hide and sometimes he'd play in the flow.

I have two opposing surges, but they're on different frequencies and time offsets so sometimes they happen together creating a crash. Sometimes they oscillate and for some periods, only one gets to go for a while. During early morning, the eastern surge runs more and vice versa at sunset.

There is a small high frequency tone as the actuators go. You can't hear it in the house, but you can in the garage. I'm sure the fish can hear it because they can anticipate the surge but can't always tell which way it's coming.

The rabbit learned from the sailfin and the purple and Naso learned it themselves since they were larger and didn't bother watching the little fish. The big guys took it a little more rough at first. They had been in a calmer environment for most of their lives and handfed, etc... So they underestimated the flow a few times.

The Naso being the beefiest tried to play a little hard doing jet fighter acrobatics though the convoluted rock work during a cross surge and scratched himself in a few places. But only once. After that, he was pretty good at judging his own swimming ability. Now he uses it a bit like a never ending pool - he goes to the opposite end and swims into the wave hard against the front of the glass. You can see the effort he exerts to get speed into it.

When he's tired, which isn't often, he goes behind the rock work where the flow is just a calm breeze.

 

[karimwassef]

It also does wonders in breaking up feuds. Any territorial disputes stop during a surge and the two opposing fish go into the rock work together.. Waiting side by side to come back into the next little squabble. A few of those events and they're feeding side by side.

It's a little like a refocus. Instead of one vs one... It's two vs the coming wave.

 

[karimwassef]

I should post some vids.

In terms of increasing the aperture to reduce speed, the current outlet is a 2" pipe into an open volume. Even an expansion to a 3" probably won't effect it much unless I resize the piping before the final elbow...

But it sounds like you're saying my slot area should be even larger to reduce speed vs. the 2" now. Ok thanks.

 

[karimwassef]

One downside to the surges, especially the cross current- slow moving or small animals have it rough. My hares bury themselves all day and only come out at night after being blown off the rocks. Snails, crabs, my nudi, urchins... They've all made trips in the air/water from a surge they couldn't foresee. Some turbos die because I don't see them and they end up on their back too long.

Some are pushed into the overflow mesh and the small ones get sump logged... My glass shrimp migrated that way along with hundreds of pods.

 

[Michael Hoaster]

"In terms of increasing the aperture to reduce speed, the current outlet is a 2" pipe into an open volume. Even an expansion to a 3" probably won't effect it much unless I resize the piping before the final elbow...

But it sounds like you're saying my slot area should be even larger to reduce speed vs. the 2" now. Ok thanks."

Yes, so maybe a long horizontal slot, or multiple pipes, all totaling much more than the 2 inch opening, to reduce velocity.

 

[karimwassef]

I wasn't thinking of multiple pipes! That's an interesting idea. Maybe come down to a T and then reduce to a couple of 1.5" pipes in parallel with wide slots.

 

[Michael Hoaster]

Right, so with reduced velocity, you get less whirlpools at the top and less dust devils on the bottom. (I think) Hey, I'm just thrilled to be part of the discussion!

Maybe you could incorporate a spoon…