90 gallon cube closed loop

[shermoen]

Good day all,

I scored an acrylic 90 cube with mh setup stand and sump for 80.00 not to long ago. Been sitting in the garage for 6 months until it warmed up so I can polish it up.

It appears to have been designed for a closed loop system and I'm wanting to experiment with that this build.
-4 bulkheads on top through the euro brace (outputs)
-2 bulkheads on back (inputs)
-tank does have an internal overflow.

I've never dont this before and am not really finding anything about sizing for a pump. (Is it the same as sizing a return pump or power heads?)

Will be:
-sps dominant
-in family room (low noise would be good.)

Budget:
-anywhere up to 500.00 possibly. (Will probably go ecotech or sicce unless there is a good budget option.)

Open to suggestions and advice on this.

 

[Hishman]

What are the bulkhead sizes for the closed loop. That will give a rough idea of what flow it will support. I would spec it for the bulkhead size.

I swear by the Jabao pumps. (Branded Jacao in EU) and have had two DC2000 running 100% and are whisper quite for years. They are Chinese/budget pumps.

 

[UncommonSense]

For noise; consider spray bars or laminar sheet bars on the outputs… I usually make my own! — sch.80 pipe with a series of neat holes, or metered width slot(s)!

 

[shermoen]

What are the bulkhead sizes for the closed loop. That will give a rough idea of what flow it will support. I would spec it for the bulkhead size.

I swear by the Jabao pumps. (Branded Jacao in EU) and have had two DC2000 running 100% and are whisper quite for years. They are Chinese/budget pumps.

The holes drilled are 1 3/4" and there are 1 1/4" bulkheads installed right now. They have 1" threads in them.

For noise; consider spray bars or laminar sheet bars on the outputs… I usually make my own! — sch.80 pipe with a series of neat holes, or metered width slot(s)!

Cool! Do you have any pictures or builds showing how you make those?

 

[UncommonSense]

The holes drilled are 1 3/4" and there are 1 1/4" bulkheads installed right now. They have 1" threads in them

Oh wow, you’re good for around 10,000gph of flow then! That seems excessive?

Cool! Do you have any pictures or builds showing how you make those?

I might have photos of a few around, or a few laying around… Give me a moment; I’ll check! — I think most of my leftover spray bars (used for an AIO hydroponic system/plant display) went to my LFS for use whenever they get seahorses in!

 

[Hishman]

Do you have pictures the closed loop bulkhead locations.

Most of the time for closed loop you’ll want a pump that alternates flow back and forth between the two bulkheads.

 

[UncommonSense]

Yup, looks like all my spray bars are at my LFS currently… they are a simple length of pipe with metered size holes drilled centered and evenly spaced along the length… I used my drill press with an XY vise mounted to its table to do this precisely! — you can also add a variety of nozzles to these holes if you choose to tap them!

I do have a double lit rain style algae scrubber I built long ago laying around still!

Here’s an example of the (poorly) slotted pipe I used to create a laminar sheet of water… this is much smaller (3/4”) than your application, obviously! I recall it had a max flow of around 450-500gph while maintaining a laminar sheet!

 

[shermoen]

Do you have pictures the closed loop bulkhead locations.

Most of the time for closed loop you’ll want a pump that alternates flow back and forth between the two bulkheads.

There are 2 holes in the front corners. 2 in the back just other side of the over flow (these were used for the return from the sump.)

I am considering cutting 2 more holes in the back corners for the closed loop.

 

[shermoen]

Yup, looks like all my spray bars are at my LFS currently… they are a simple length of pipe with metered size holes drilled centered and evenly spaced along the length… I used my drill press with an XY vise mounted to its table to do this precisely! — you can also add a variety of nozzles to these holes if you choose to tap them!

I do have a double lit rain style algae scrubber I built long ago laying around still!

Here’s an example of the (poorly) slotted pipe I used to create a laminar sheet of water… this is much smaller (3/4”) than your application, obviously! I recall it had a max flow of around 450-500gph while maintaining a laminar sheet!

Thanks for that! I could make that no problem. What's the plastic screen do?

 

[shermoen]

Here's pictures of the setup, pretty cheesy hood for MH lamp.

 

[UncommonSense]

Thanks for that! I could make that no problem. What's the plastic screen do?

In the case of that particular part; it’s #7 knitting mesh, roughed up by hand with a hole saw until I had a palmful of plastic shavings off it… this serves as a high surface area substrate for hair algae to cultivate, when lit from both sides!

I can imagine it also helped the water flow as a laminar sheet at full slot width for 6-8 inches of vertical drop…

I would imagine there are plenty of alternative methods to achieve the same effect that are far less ugly, and aren’t intended specifically to cultivate algae! Possibly a thin (1-2mm) sheet of polycarbonate? (This could also be illuminated from inside the plumbing by waterproof RGB LEDs, if you really want to get fancy!)

 

[UncommonSense]

Here's pictures of the setup, pretty cheesy hood for MH lamp.

Hold up!

Can we see a close up of that front left corner seam in the display? It’s hard to say from the first photo, but there might be something going on there…

 

[shermoen]

Hold up!

Can we see a close up of that front left corner seam in the display? It’s hard to say from the first photo, but there might be something going on there…

What you got?

 

[UncommonSense]

Hmm… That looks suspiciously like a stress related bubble/bubbles in the welded joint between those two panes… perhaps try shining a flashlight through the thickness of the acrylic front viewing pane along that corner to see if they are indeed inside the joint?

 

[Hishman]

I couldn’t tell if you have 3 bulkheads in the overflow but your plumbing could look like this. If you only have two bulkheads in the return that tank likely isn’t set up for closed loop. If it has to in the bulkhead and two in the outside it’s probably dual drain and dual return.

Red is the closed loop. With your bulkheads 8-12k pump would be fine. DC pumps can be turned way down so you can tune it however you need. You’ll lose GPH from head pressure and fittings.

Blue is your overflow and backup overflow. Put a valve on the lower height overflow and close the valve until the water height gets close to your backup to make it silent.

Yellow is return. You can drill the overflow for a single return or tee it off to have two return nozzles. Most people say you only need 1-2 tank turnover rate per hour.

 

[Hishman]

If you just have 2 bulkheads in overflow here is a standard way to plumb it with your two return. I would run two return pumps personally.

 

[shermoen]

Hmm… That looks suspiciously like a stress related bubble/bubbles in the welded joint between those two panes… perhaps try shining a flashlight through the thickness of the acrylic front viewing pane along that corner to see if they are indeed inside the joint?

I think you may be right. Kind of a bummer,

but better than a flooded basement!

 

[UncommonSense]

I wholeheartedly agree!! What thickness is the acrylic? I got quoted $60/ft2 by my local plastics shop recently for 1/2”!

Edit: it might be salvageable… I’m far from an expert in acrylic fabrication, but I don’t see why solvent welding a square or triangular rod of acrylic into each of the interior corners couldn’t save it… maybe @Troylee or one of the other plastics masters can chime in?

 

[shermoen]

It is 1/2". The guy i got the tank from was running it for about a 2 years before he upgraded. He got it used as well.

I dont know enough about acrylic to chance it. Probably just set it out on the curb if there's no way to fix it.

 

[UncommonSense]

It is 1/2". The guy i got the tank from was running it for about a 2 years before he upgraded. He got it used as well.

I dont know enough about acrylic to chance it. Probably just set it out on the curb if there's no way to fix it.

Well, maybe bring it in and see if your local plastics fabrication shop can do anything to help you out before you give up on it completely? That wouldn’t be a cheap tank to replace!