New tank plumbing ideas

[Russ1]

Hey guys!
Would just like your input on some plumbing ideas for a new 400 gal tank built into the wall. I had the thought of having the whole back of the tank be an overflow with two 2 inch drains and put Durso standpipes in each. Then have two intakes for two closed loop recirculating pumps near the bottom of the overflow box. My theory is that if you had the capacity for huge amounts of water flow through the overflow box and you maintained a high water level in the overflow box then you could intake for your recirculating pumps inside the overflow. The main problem that i have had in the past when I tried to do this was sucking the overflow dry. I think esthetically, this would look totally cool! Any ideas? The sky is the limit! Russ

 

[Mouse]

I think you would either suck em dry, or get too many bubbles in the system. Besides a closed loop that feeds from an overflow and feeds into the tank isn't really a closed loop. JMO, but im sure someone could clear this up.

 

[wastedincome420]

Hey Russ Your a "local reefer"
Its nice to see some one close by tha ejoys the hobby

I'm in the middle of setting up a 105g reef with a closed loop,etc. I would suggest against using over flow for the intake on a closed loop. You want to make sure you dont suck air in to loop. The over flow plan sound good, there is some one else that did that and I'll go back and look for it for you. I think that you can still use your overflow plan and just put your "CL" intakes half way down
So who's your LFS??Inland??Have you been to "little shop of pets" in ports.??If not you have to sheck em' out they have a very large selection of corals and fish

 

[M.E.Milz]

I am planning something similar for my new tank (78"x32"x36"high), although I will not be using a full width overflow (20"x6").

The bottom of the overflow will have 4 separate 1.5" bulkhead drains. 2 of these will feed water to the sump. The other 2 will each connect directly to a separate pump, which will then return water through a 1" seaswirl (for 2 separate closed loops).

To keep air from being sucked into the closed loop intakes, Durso standpipes will be used on the other 2 drain bulkheads (the ones connected to the sump). Thus, the water level in the overflow should stay at the top of the standpipes, which will be at least 30" above the top of the closed loop intakes.

I decided to go this route instead of having the closed loop intakes directly in the tank for a couple of reasons:

1) All of the bulkheads are in the overflow compartment. Thus, I can fix leaks without draining the tank.

2) I have much better access to drain bulkheads for cleaning (as opposed to being in the back wall of teh tank, where it would end up behind the rock).

As for sucking the overflow dry, I cannot see how this would happen, even if the sump return pump quits. But since I have not set this tank up yet, I cannot prove it.

As an alternative, you may want to look at some of the other threads on closed loops. I recall that someone had the intake bulkheads for the closed loops in the overflow compartment, but then had a pipe connecting the bulkhead to another bulkhead in the partition wall (this is a little hard to explain). This allowed him to have the intake taking water directly from the tank, but without having to install bulkheads in the tank walls.

 

[Anonymous]

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by Mouse:
<strong>I think you would either suck em dry, or get too many bubbles in the system.</strong><hr></blockquote>

Theoretically it shouldn't suck the overflow dry unless the tank overflows. Water in should equal water out.

However your bubble comment is an excellent point. An overflow by design usually has quite a bit of bubbles. Russ if you were gonna do this you might wanna engineer some sort of wier or other method to prevent bubbles from being returned to the tank.

 

[Russ1]

The main thing to consider here is this. Your overflow fence must be able to accommodate the water flow from your sump as well as the water flow from your recirculating pumps. If it can do this, you can raise the water level in the overflow with the Durso standpipes so that you don't have a noisey waterfall. I think the key here is that your intake for your recirculating pumps must be towards the bottom of the overflow box. My experience in the past has been not a bubble problem but a water volume over the overflow fence problem ie., the fence can't handle the added volume of water from the recirculating pumps. My idea, a huge overflow that can accommodate the volume. Also, it would seem to me that it would surface skim the entire length of the tank. I'm thinking of a Chevy 454 for my main pump! Just kidding. Any thoughts are welcome. Russ

 

[Jeff Hood]

Hey Russ, I think your Idea is very sound and a very good one. Just make sure your overflow is designed right and the slits are deep and wide enough to handle the flow you want to achieve. Also if your overflows are external and your tank is acrylic make sure they overbuild them and make the seams strong if you will leave them completly full of water all the time to handle all the added weight your stand pipes make. MY Overflows have no support on the bottom like the tank and I was afraid to keep 20 gallons of water in there all the time. Its probably very safe but did not want to chance it.

My slits in my external overflows are 1/2 inches wide and 1.5 inches tall. They flow around 1000 gph per foot of run Max. That is how fast they will handle with the water up against the center brace and the water level is stable. Any faster and it starts to over flow. To have my water level where I want it I can only run about 750 to 800 gph per foot of run. These numbers are approx. and determined by the head calculations and performance curves of my pumps.
Depending on the length of your tank you could be able to handle flow from around 5000 to 6000 gph. My max is around 4000 gph total flow through my overflows and I have 4 feet total run. I run them at 3000 gph. If you want more make more feet of run or bigger slots.

I use a closed loop with strainers so that is how I got around it. My total turnover including closed loops will be approx. 9000 gph actual flow using 4 ampmaster pumps. Tank is approx. 500 gallons.

Jeff

 

[Russ1]

Jeff,
Great thoughts! Actually, my overflow will be internal, it's just going to be the whole back of the tank both width and heighth. Depth will be about 6 inches. This will all be supported by the stand which the carpenter will build. The drains will be cut into the bottom of the stand. The intakes for the recirc pumps could actually be in the side of the overflow near the bottom. I had thought about 8-10 return jets, say 2 on each side and 4-6 across the back. The ones across the back would be plumbed through the overflow box. My return pump at my office is a Jacuzzi 1/2 hp due to the high head pressure. It also runs the skimmer. There will be no head pressure here but I like the Jacuzzi. The recirc pumps (2) will be on each side of the tank. I've also considered making the tank higher and incorporating a dump bucket but this is just kinda a thought. This whole tank will be built into a wall with a room of its own. A deep sink will be in the room with a spray nozzel for cleaning equipment. This hobby is out of control!! Russ

 

[Jeff Hood]

Hey Russ, Sounds like you have gone off the deep end like me. I have just completed a room similar to what you are describing. I have a sink and everything also. The room also has its own A/C unit and portable heater.
What are the dimentions of your tank going to be? I think your going to be much safer with the overflows the way you are building them if you are keeping them full that way. Basically they are not really closed loops but a second sump that is not below the tank just behind it because you are flowing water between two compartments that are separated. Closed loops are circulation in one compartment only. Its just semantics really so don't worry about it in the long run. The main thing is you are getting the current you need for your animals. There is really no differance between your full overflow and a sump other than location so all things applied to a sump including the possible need for baffles and overflow size apply. It should work great if everything is sized correctly. Should look great and be very efficient.
Be sure to domument your progress as you go and keep everybody up to date with pictures. The planning and the building of a monster like this is a lot of fun.

Jeff

 

[Russ1]

Jeff,
I'm thinking 72x34x38. Possibly 84 wide. The viewing would only be 72(or 84)x30. This will allow the front of the DSB to not show and also the water level to be above the viewing area. I would go deeper front to back but the opening into my basement is only 35 inches wide with the door off! 402 gal. or 470 gal. Russ

 

[Jeff Hood]

Sounds Cool. Its good you are going as deep as you can front to back. For one thing you will like the aquascaping much better and with a thick tank and water the actual view looks compressed when full. I would rather have a deeper tank than wider to give a better 3d effect. Both would be nice though.

Jeff

 

[M.E.Milz]

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote

The main thing to consider here is this. Your overflow fence must be able to accommodate the water flow from your sump as well as the water flow from your recirculating pumps. If it can do this, you can raise the water level in the overflow with the Durso standpipes so that you don't have a noisey waterfall. I think the key here is that your intake for your recirculating pumps must be towards the bottom of the overflow box.

Exactly what I am thinking. As for enough capacity over the overflow partition, trying comparing the area to the area of the drains. For example, if I use a total of 4x 1.5" drain blukheads, the total cross-sectional area of these bulkheads is approximately 4 x 0.75 x 0.75 x 3.14 = 7.1 sq.in. If I use a partition having a length of 30" (6" + 6" + 18"), and lets say that the grating occupies an area of 1/5 of that, then my actual effective length = 24". The height of the water flowing over the partition = 7.1/24 = 0.29".

I know that this assumes equal flow rates, but you get the idea that by comparing the length of the overflow partition to the cross-section area of the drain bulkheads, you may discover that you do not need to extend the partition the entire length of the tank (although it certainly won't hurt). However, the shorter the length of the partition, the higher the water level in the tank will rise when the pumps are on, and the more water will end up in the sump when the pumps are turned off.

[ February 18, 2002: Message edited by: M.E.Milz ]</p>

 

[Russ1]

Also consider this. When you put your arm or anything else in the tank your overflow needs to have the capacity to handle it. Also if you have the tank made, it's very difficult to add another internal overflow. When coraline algae builds up on the overflow fence, that will cut back your flow. I know you need to keep it clean but why not overbuild it so you have some flexibility. Also if you are going to have a dump bucket, you see my point?

 

[M.E.Milz]

Russ, I agree. I was merely attempting to point out that the length of the overflow partition will probably not be the limiting factor in your circulation system.