MitchM tank build

[mr.wilson]

The lids will raise the tank temp at least 5˚F. They will limit gas exchange slightly, but it isn't a major concern. You will get condensation and salt creep/spray and the lids will become cloudy further diffusing light. If you are using metal halide lighting, the lids will warp considerably. Flipping them weekly helps keep them straight.

[MitchM]

Originally Posted by mr.wilson

Sorry, if I'm making an already confusing discussion, even more so, but I have a few questions about your design. There are four holes in the top for the (now two) Seaswirls, but the plumbing is coming up from within the tank?

Hi Mr. Wilson,

Thanks for your input, I've been following your work on RC.
The original design was to have closed loops with two Dart pumps. Each pump would have 2 of the rear intakes and supply 2 of the seaswirls. The pumps were to be mounted on the back of the stand itself just below the level of the tank. This mounting would be similar to the mounting of the closed loop pumps on the Penn State main display tank. As it is a closed loop system, head loss would be minimized and friction would be minimized by keeping the actual plumbing run as short as possible.
When I ordered the tank I had not determined the sump return and had intended on drilling the tank as needed for that.

At this point I am going to be using only the front two seaswirls and dropping two supply pipes from the sump down the two rear holes that were originally going to hold the two rear seaswirls. That means that I will have the 4 rear intakes for 1 Dart pump supplying the two front seaswirls.

Originally Posted by mr.wilson

...That 4300 GPH quickly turns into 2200GPH with 6' of head, a ball valve, check valve, and a few elbows. If the two Seaswirls are on a closed loop they will also have more headloss than your proposed tidal system. How many effluent lines will you have on your closed loop? I assume you are dropping down to 1" at the Seaswirls. You may only have 1500GPH on your closed loop by the time you finish up.

There are no check valves in my design. I have not had good experiences with them in the past.

Originally Posted by mr.wilson

may want to consider a pressure rated sump return pump like a Blueline or Iwaki 100 for the two Seaswirls and use four 1.5" effluent lines (reduced to 1" at the tank) for each of the two Superdart closed loops.

As the system sits now, 1 dart pump will be supplying close to the limit of 2 seaswirls rated GPH.

Originally Posted by mr.wilson

of the benefits of an OM unit over solenoids (other than cost and noise), is that the OM will allow some passive flow through the closed line(s). This is beneficial considering that these lines will be off for 5 hours and will become anaerobic. Also keep in mind that you may have some air in the lines as they fire back up again. The bubbles aren't a big problem for corals or fish, but they do make a mess of your lighting (salt spray). The Om unit will not allow air into the line when it is cycled "off". The OM has a soft on/off cycle so you don't dislodge biofilms from your plumbing every time it changes path/direction, as you would with an abrupt cycle.

The cycle planned is actually 5 hours on, 1 hour off. The outlets for the sump return will be designed to allow for drainback of the water to the sump, so there will be no water remaining in the plumbing lines. There will be air coming back through the lines, but given the closed top of the aquarium, the lights will not be affected. I'm not sure what the effect will be from any biofilm being dislodged on a regular basis from the plumbing.

Originally Posted by mr.wilson

I'm leery of turning pumps on and off on frequent cycles, especially pumps that are not magnetically coupled such as the Sequence line. I find with these pumps, particularly as sump returns, perform and sound differently as the impeller settles in varying positions. If you set it and forget it, these pumps are reliable. Pumps with a soft on/off are another story.

The effect of the on/off cycles are a concern of mine with the Dart pump and I am open to changing to a different pump for that application.

Originally Posted by mr.wilson

Are you using the check valve as an air intake or to physically stop water flow (back siphon)? Is it a swing, ball or wye style check valve?

Again, I will not be using a check valve. The back siphon will be allowed to happen.

Originally Posted by mr.wilson

I'm not sure if you will achieve your tidal sequence if you are just using one pump to go through the cycle.

My original post to Oceans Motions was to see if they could come up with a design that could accomplish just that. Paul at OM thinks he has a non-solenoid controlled design, and I am waiting to hear back on the final results

[MitchM]

Originally Posted by untamed

....

I like your idea of placing coral where the food appears to be. It is going to test your patience to wait that long to add corals!

The longer I think about it, the less I want to put in this tank. I want to be sure that whatever I put in there, I want to be able to feed enough.
I'm in no rush to stock it.

[MitchM]

I got the basic stand frame done today. I still want to put two joists with hangers in the middle, but LVL's need special hangers and nails. I would like to find someone in Calgary that stocks them. Home Depot wants 10 - 14 days to order them in.

I used 1-3/4 X 9-1/2 LVL for the beams (doubled up front and back) and 6 x 6 treated dimensional lumber for the legs. I'll be moving the tank into place using an engine hoist, so I needed clear floor under the stand to allow for the hoist wheels. With the strength of the beams, I won't need any other support underneath, but I may still frame up a wall under the back and sides then sheet it with plywood to prevent racking of the stand once the tank is loaded with water and rocks.
Alternatively, I could put in some knee braces to give it a timberframe look.

I like using engineered lumber for stands because it's simple, beefy and straight.








I used this laser level to level things:

[lastlight]

Wow that's one simply way to do legs! Although I doubt I have the skills to cut posts like that myself.

Does Rona/Home Depot sell those LVLs right in the store? Good idea!

[MitchM]

With a pencil lay out the area to be removed.
Tools required to cut the posts are:
circular saw
reciprocating saw

Use a chisel and block plane to clean up the cuts. It takes about 10 minutes per post.

Rona or HD doesn't stock the LVL's. Go to the contractor desk and order them. I think they'll round up the size to the nearest 6" and give you about 1/2" extra length to square off each end. There are a lot of different sizes available.