125g Overflow Question

[RockyProndoa]

I recently purchased a used 125g tank/stand/hood and am planning on getting back into the saltwater hobby with a reef tank. Alot has changed since I left (I had a wet/dry on my 55g reef many moons ago!)...so, here is my question since I am still trying to understand all of the new methods.

My tank is equipped with a 1" bulkhead drilled into the BOTTOM left rear of the tank. A black acrylic partition creates the overflow, with a durso standpipe taking the water down quietly (hopefully!).

The return is drilled into the REAR back right near the top via a 3/4" bulkhead fitting.

Question 1: Is this one drain going to be enough to get adequate circulation through my tank? If I would like 5x tank turnover, I would need 750 gph. Using the calculator on the homepage, I get a slightly larger than 1" drain with 11" of linear overflow. (I believe the two partitions added together would come very close to 11" total).

Question 2: Durso standpipes...are they really quiet? I see alot of talk about the BeanAnimal design and similar. What are opinions on a Durso?

Question 3: Return - I would think that if I am draining water through a 1" drain and return is via a 3/4" pipe, I have a mismatch in water circulation and in essence will only be able to utilize 3/4" of the 1" drain pipe (in theory). Should I attempt to drill a second return for a bulkhead fitting in the rear of the tank? If so, where?

Question 4: Critique, help, etc. I am looking for ideas on how to improve, if necessary BEFORE I buy anything. I want to take it slow and do things the right way and learn as much as I can before it's filled with water.

Thanks for all of the help!

 

[Twistofer]

Welcome Back to Reefing...

Q1. 1" Durso should be sufficient to handle the overflow.

Q2. My 90 gal had a Durso and it was plenty quiet. I have no experience with the BeanAnimal design; you can search the forum for threads about it. There has been a lot of info here.

Q3. The return is governed by your pump. I was able to run about 900 through a 3/4" in my 90 gal. The mismatch often comes when the outflow cannot keep up with the pump's flow. If you're concerned, note that most pumps (rated up to about 1600 ghp) will have a 3/4" MTP output connection for your return flow.

Q4. I think you're doing great. Keep us posted with your design.

 

[RockyProndoa]

Thanks for the reply. So you think the single drain will be sufficient for that size tank? Also, I am concerned with the drain being solely in one corner of the tank. I have noted that many people have a drain in each corner, assumedly to aid in surface skimming and even water distribution. Does anyone see this as being a problem?

As far as the flow, I would simply be able to "dial-in" the pump to the correct flow rate. I am thinking an Eheim 1260/1262 for this.

I would like to have two returns plumbed into the tank, but very hesitant to drill through the 1/2" thick glass and risk shattering it and ruining the tank. Perhaps I will practice on my sump first!

Any more opinions/thoughts are welcome.

 

[Morbeus]

I have a 90g "reef ready" tank with a large overflow box and two 1" bulkheads in the bottom. Much like you I was concerned about drain adequacy and having a backup just in case so instead of using one as drain and one as return I am using one as the main drain and one as an "emergency" drain. The main drain is approx. 6" lower than the emergency and has a gate valve that I got from BRS on it so I can adjust the flow and if you create a siphon instead of an air infused drain, it should be quieter and flow more. I am not sure if your 3/4 return has an overflow box but either way you may be able to use that as your emergency and then create a return that goes over the side of the tank. That is what I did and my return has a gate valve and a wye check valve. I hard plumbed it out of PVC and spray painted it black (all except check and gate valve) because my back is see through. My drain method is called the herbie method (google it) see also gmacreef.com for a good outline on it. This is supposed to be at least as quiet as durso or beananimal but I have not used those so I cannot render a personal opinion that is experience based. If you do gate valves on both the return and drain you should be able to match up the flow pretty easily.

Also, whatever you decide I advise using a bigger rather than smaller sump because that will give you more margin of error with your flow and will give you more future flexibility, ie. more flow later for higher flow setup, etc. If you are going to be using hard PVC plumbing, remember to dry fit first and then be sure to budget some length loss when you cement it together as you will lose some length from that. Be sure to test it out too for leaks and functionality with your return pump.

There is a drain flow calculator on the home page of RC and also a return or head loss calculator which you may find helpful.

Good luck.

 

[RockyProndoa]

Thanks Morbeus for the reply. I had considered using the return bulkhead as an emergency drain. My concern is that it is on the rear panel of the tank and not on the bottom as most drains are. In the event of a main drain failure, would there be enough flow through this to provide any benefit? (A bottom drain works with the pressure of gravity - a rear drain would only work with the outward pressure of water).

Now that I am thinking about...I could drill the bottom of the tank in the right rear corner, creating another overflow, and still use the return bulkhead that is piped on the rear wall. I would just have to add some flex fittings to pipe it out of the overflow box. (On a side note, I see people using these self-made diagrams...what program are people using to do that? This may be easier if I created some diagrams to visualize.)

I was a cabinetmaker for many years, so using tools is fine, but wood is my specialty, not glass and I am hesitant to drill an expensive tank if I don't have to.

Thanks again for all of the info and opinions, it is certainly helping!

 

[RockyProndoa]

Shameful bump....anyone else with thoughts?

 

[Morbeus]

Honestly I would only drill if you have to and I do not think you have to. To answer your question, a herbie system can be set up with back of the tank drains just as easy as bottom drains, or a mix of the two - this is where the importance of the gate valves come in. They allow for fine tuning - much better than ball valves in my opinion and based on professional commentary. So again I would have your main drain be the bottom one and the backup the 3/4 on the back- as long as you are not trying to go crazy with high flow, this should work. Plus you could silicone an overflow to the portion with the 3/4 to cut down on pressure and inadvertent "lapping" if you will use a wave maker depending on where the bulkhead is located. You would also be fine in doing a 3/4 to 1" piece (larger piece on the inside of the tank) with a strainer to avoid fish getting sucked in. The point of the emergency in the herbie system other than backup drainage is to make noise to let you know that your main drain is not doing its job. You just need to make sure 3/4 can handle the flow and if your goal is 750gph a siphoned 3/4 should be adequate. The beautiful part is that you can test it without committing to it. Plus remember if you are doing a live rock heavy tank, you will not have 125g to contend with at the end of the day. So as you call it 5x it will be a higher "x" multiple in actuality.

If you do drill the bottom - can you not drill close to the existing drain and still remain inside the overflow box? This is how mine is set up. Two drains side by side are no problem. With herbie you would have one approx. 6" lower (the main one) inside the overflow than the higher one (emergency) which you would place just about 1/4" below the bottom of the baffle teeth.

You are definitely on the right track Rocky.

 

[RockyProndoa]

Morbeus:

Thanks for the reply again! I somehow missed your response on this thread until now, so I apologize for the late reply. I agree the 3/4" should be the emergency...but help me understand how it will actually work?

Water flows from tank to sump via two methods, either gravity or siphon, or a combination of the two. Considering the 3/4" bulkhead is mounted on the upper right hand BACK corner of the tank, wouldn't the only initial driving force moving water out of the tank be the outward pressure exerted by the water itself? If that is true, the water in the tank would fill faster than it would drain through this emergency drain, thus overflowing my tank? Or am I missing some simple laws of physics here?

As far as drilling a hole next to the existing one, no, there isn't enough room...unless I take off the acrylic partition in lieu of a larger one so that there is adequate room for another hole; this is my debate - I'd hate to ruin a tank by breaking the bottom glass!

As for stocking, my long-term plans are a live-rock and coral heavy tank with a medium bio-load. Your point about 750 being greater than 5x tank volume makes sense, so in that regard I do think I am well within the limits for a single 3/4" drain with an emergency backup.

Either way, it sounds like I am going to have to drill the tank unless I want to pipe the return over the back of the tank as many here do.

To summarize, am I being overy cautious about this drain setup? Does my thought process about a rear drain not make sense? Anyone want to come drill the tank for me? lol...

Thanks for the help and opinions everyone!

 

[Morbeus]

What I ended up choosing is covered at gmacreef.com which has a few small articles on drainage systems for tanks. I stumbled upon it after I already had mine designed and built.

Google the herbie method and if you design it right, the siphon will begin on its own as long as you are not introducing air into the line and only gravity. Mine did. You can test without committing and if you do not like it and want to drill you have that option preserved. The siphoned drain can clear a good amount of water (I think you will be surprised) but again you have to do what you feel comfortable with, after all it's your floor. Although I do have mine set up on expensive quarter rift and sewn oak hardwood. But then again I do not have plastic on my couches either.

On the contrary, I think you are being smart and not too cautious - only fools rush in. My configuration took me awhile too. The over the back return is not bad mine looks great and works great but you have to love it. It is your tank and your house. Do what you think is best.

I am sure whatever you choose will end up working out in the long run. Just keep thinking redundancy in your design and test different scenarios.

Post pics when you are ready. And most of all enjoy it!