Rimless drilled tank advice?

[Jim Miller]

I'm getting ready to go out for quotes on a 75g (48x21x18) or maybe a 90g (48x24x18) rimless tank drilled for bulkheads. I'm leaning toward 90g since I'll need to stand on a stool to work on it anyway and my arms are long enough.

One supplier I'm going to quote is Coast to Coast asking for Starphire on three sides.

Any recommendations on glass thickness for that size?

My current plan is for a single 1" SCH80 double threaded bulkhead in each of the rear corners centered 4"x4" from side and rear respectively.

I'm assuming that I'll thread 1" ball valves onto each of the bulkheads on the bottom and plumb mostly soft 5/8" from there to 2078 Eheim, RG diffuser and ETH300. Loclines on output for spray direction.

My questions:

Is 4" from side and back sufficient for rotational clearances for thread mounting the ball valve? Overkill? (Stand to be ADA style with 3/4" cherry ply construction.)

If only using a single set of bulkheads is 1" enough or should I go bigger?

Am I making a mistake by going with a single set of bulkheads?

CTC is a day trip away which means I can just go pick it up. They appear to be a quality shop.

Any other quality suppliers recommended within a day's roundtrip from Baltimore?

Any and all input appreciated. I'd like to get this on order this week.

Thanks!

Jim

 

[Biollante]

Sounds Like You Will Have A Very Nice Tank

Hi Jim,

Low-iron glass is great.

Unless you think there will be a lot of viewing from the ends, as opposed to just walking past, I recommend just the front in the Starphire glass.

With a safety factor of 3.0, 7mm glass is great, if you are dealing in fractional glass you will probably end with 3/8 inch (9.525 mm) that give you safety factor of better than 5.

I really recommend at least two 1.25 inch (31.75 mm) bulkheads, 1.5 inch (38.1 mm). I prefer through the bottom of the tank.

I can recommend Glasscages.com http://www.glasscages.com/?sAction=Home, though I think you will end up with the 3/8 inch glass with them. They are in Tennessee though so that would involve shipping.

Good luck,

Biollante

 

[Jim Miller]

Biollante

So that would be two pair of 1.25" bulkheads, each requiring 1.5" holes? Just wanted to be clear.

Bottom drilling for sure.

In the location picked for the tank we will be viewing often from the ends as well. Any reason other than cost to avoid Starphire ends?

Thanks!

Jim

 

[Biollante]

Sorry Meant "Or"

Hi Jim,

Sorry, I really was not clear.

I am recommending either 1.25 or 1.5 inch bulkheads.

I tend to recommend the larger 1.5 inch bulkheads.

Cost was my only consideration regarding the end glass, my understanding is the low iron glass is only marginally more brittle.

Of course make sure the bottom glass is not tempered if you are planning on drilling. Many manufacturers like to use tempered glass on the bottom, for whatever reasons. Obviously if this is a custom build and “they” are doing the drilling it won't be a problem.

One other minor point, make sure the glass ends and edges are “polished.” Polished for a better fit, better seal and to keep you from cutting yourself. Again something most will include automatically, though some in "low-balling" a bid will bring this up after "they" have the deal. Should you decide to build it yourself, make sure the glass is cut and polished. :gw

Have fun...

Biollante

 

[Jim Miller]

Biollante

Thanks for the size clarification. I'll go to HomeDepot this morning to look at valve dimensions to ensure adequate rotational clearance for mounting.

CTC or who ever I chose will do the drilling. I'll make sure to verify polished edges.

I just wanted to clarify one last thing: are you recommending 4 bottom holes or 2 bottom holes?

I would guess that 2 holes sized for 1.5" bulkheads could pass a lot of water at low loss.

Thanks!

Jim

 

[Gerryd]

Jim,

Go with the 90 for sure as the footprint is similar..starfire on 3 sides for sure if all are viewable...

Two 1.5" bulkheads would deliver all of the flow to any filter you want or allow for two filters..does the eheim you have support two intakes?

Keep in mind that if you have a 1.5" intake and use 5/8 tubing that the tubing size will now control the flow to the filters..Watch carefully to ensure you don't restrict this nice intake....go larger PIPE diameter whenever possible..you never know when a pump or component will be resized or replaced..

Drilling extra OUTLET holes now will eliminate the need for over the tank outlets.... Just use shorter pipe and loc-line and the outlets can all be optimally placed and hidden easily. Plus, less head to push it over the tank wall...

So, one intake at each side say, and then 2-4 outlets. I'd place one in the 3 corners for sure, and maybe one in the back middle. Keep in mind how you intend to scape it someday, as these may be in the way

May as well make it as nice/flexible now, so less worries later.

 

[Jim Miller]

Gerry

The Eheim 2078 has a single 5/8" intake (16mm). I plan to keep the length of the lines minimal but with enough slack to allow servicing. I plan to use mostly softline and large radius bends to avoid turbulent loss due to elbows. Some softline is required to hook things up anyway so I don't think I'd benefit from minimal lengths of large diameter PVC once transition turbulence is taken into account. I'm open to advice in this however!

I think you meant to say back corners so outlets in 2 corners, with perhaps an additional outlet in the middle for 3, right? Do the outlets need to be 1.5" as well?

Edit: I plan to put full size unions on the opposite side of the ball valves from the tank bottom so that I can easily modify the undertank plumbing including filter additions and size changes.

Any reason for multiple inlets if a single corner placed inlet is 1.5"? Edit: I now see you said 2 inlets of 1.5"...

Thanks!

Jim

 

[Gerryd]

Jim,

A single 1.5 inlet would be fine I think for a 90 gal. Up to you for placement. Or two smaller inlets one on each end/corner?

Outlets can be smaller, but keep in mind again that a smaller diameter pipe will reduce total volume, but increase velocity.

So, several 3/4 outlets would work really well. Plus be hidden as a bonus...

Using unions and ball valves is a really good idea..here is a pic of my DIY plumbing for my 180....using plenty of both

View attachment 1951

 

[Gerryd]

Jim,

Please note that inlets/outlets can be CAPPED so do not have to be used...

 

[Jim Miller]

Gerry,

Hoover Dam just called. They want their plumbing back! just kidding...

Seriously, many of the tanks I've seen with such plumbing are 180g monsters apparently meant for commercial installation or university research.

My first requirement is domestic tranquility which translates to silent operation, no mess and looks pretty in all aspects. This will be in the main living area between family room and kitchen. In addition to personal preference my handicapped daughter has a big problem dealing with droning noises so I'm sticking with Eheim regardless of cost.

The bottom drilling is a means to keep the tank from looking like a science experiment. I don't expect to be re-scaping the tank frequently, perhaps once a year as my tastes change. I'm willing to live with fixed placement in the corners. This won't be a "high tinker factor" hobby for me. I have ham radio for that!

I looked at the fitting sizes associated with 1.5" fittings and they are enormous compared to the dimensions of the 4ft tank I'm planning. I managed to find the 180g Barr thread over on TPT and read all of it and it seems like he went with single 1" SCH80 in each of the "back" corners. Doing the math, the area of a 1" bulkhead is more than twice that of a 5/8" fitting which is the size of the pumps under consideration. That would seem to make practical a second parallel loop to add other features or flow under the tank and combine inputs and outputs to the tank itself.

I've asked for a quote on the 90g/Starphire and I can always change my bulkhead decision as long as it is before construction begins.

If I'm really missing something I'd appreciate more feedback. I'm a retired engineer, I'm used to give and take. Please don't misinterpret my comments as ungrateful!

Thanks

jim

 

[Jim Miller]

As part of the bulkhead decision I'm mulling over using thread/thread vs thread/slip bulkheads. I'm leaning toward thread/thread to ensure that the bits underneath the substrate don't inadvertently come disconnected while doing random maintenance. I thought by having the threads at the bulkhead with a piece extending above the substrate before going all slip would be a better choice.

Is this a good choice?

Thanks

jim

 

[Gerryd]

Jim,

I have had slip bulkheads for >10 yrs with no issues...

Just use a section of pvc that would span the depth of the substrate... so the intake or outlet would only be visible. Even slip will not easily 'rock' or wiggle out of place. Plus, we are not talking high pressure here either...

Just remember to post one of those little construction flags at each site, to caution maintenance workers about important pipework underneath

 

[shoggoth43]

Someone did some flow experiments with different size bulkheads a few years ago. 3/4" was good for 150GPH as a straight standpipe. If you kept air out of it, like a bulkhead on the bottom, you could easily double that. 1" was ~350, 1.5" was 600, and 2" was something like 1350 GPH. Again, double these for no air. What was also interesting in these experiments is how much a strainer reduced the flow. The 1" usual strainer you find cut the flow rate in half. 3/4 was cut down to less than half. The bigger sizes didn't lose as much percentage wise.

You can find bulkhead fittings which use standard pipe thread on the outside as well. This would let you run say a 1" bulkhead and then thread on a 1.25 or 1.5" pipe on the outside of the bulkhead. This may be useful for those who run larger pumps or maybe in an overflow application. I think these are usually sch. 80 and I recall something about a white securing ring vs. the usual black or grey. That may just be me combining random facts though.

-
S

 

[Jim Miller]

I read similar water-only "freefall" numbers for those size orifices at another site. I think it was flexpvc.com. Since a pump produces a partial vacuum below the bulkhead then some of the 15psi due to air pressure would assist the flow I should think. A 2ft column of water only produces 1psi so I would think even a partial vacuum would be significant in comparison. Maybe I'm missing something.

Most of the cannisters I've seen only have 5/8" tubing for inlet/outlet. I'm planning to limit the length of that tubing however to the minimum necessary. If I need any significant length of flexible tubing other than directly at the cannister I plan on using 1" flexible PVC. The Eheim I've chosen has a flow of 450gph which I think shouldn't be limited by a 1" bulkhead. However the strainer could definitely be a limiter. I've planned on getting both a 3" and a 6" strainer to compare. Not sure about the impact of a prefilter sponge however. Seems like that could be the real issue for flowrate. Since the Eheim has a coarse filter as the first stage a prefilter on the intake might be overkill. Lots to think about.

I've inquired about making a change to my order from 1" to 1.5" bulkheads. I can always reduce on either side...

Thanks

Jim

 

[shoggoth43]

If you go with 1.5 you'll definitely be able to do anything you want to with the tank, now or later on if you decide you feel the need to imprison small reef animals. You may be able to go with 1.25" bulkheads instead of the 1.5". They'll be smaller but still give you getter flow than the 1" and maybe the strainer effect won't be as significant.

I found the site.

http://www.wetwebmedia.com/BulkheadFloRateArt.htm

-
S

 

[Jim Miller]

I've got room so I'll go big. I can always use reducers.

I like plants but never say never.

Tnx

Jim