New Sump

pdiehm · Oct 22, 2015

Don't plan on using a fuge at this time, but wanted to have it plumbed for it, and the sump built for it.
in the picture you can see the new fuge light/work area light. I cut part of the back panel off so I can put my ATO float on the back wall, and the apex probe holder is in the right front corner.

Bubble trap is about 3/4" apart, and I know it'll flow through the sump slower, but that's what I had to use as a spacer.

trimmed the siphon drain down because with the 10" baffle (it was 9" and I was reading you want your baffles at the maximum recommended for skimmers because you can always raise to get performance) because it would be 2" deep, and now it's 3/4-1" and should purge air better. Looked down the siphon drain and my gate valve is almost fully closed, just a small crescent moon opening. Probably upgrading pumps on black friday sales to a deepwater aquatics bldc 8 or 10.

Would like to redesign the return line to eliminate the 90 degree elbows (I have 4 of them), but I don't know enough about making a more efficient design.

lemonyx · Oct 23, 2015

Use 2 45's elbows to soften the corner. My concern is when it's running and the return is turned off , how much room do you have for the water that drains back?

pdiehm · Oct 23, 2015

I tested it. My return isn't that deep. And sump fills about 3" (basically just under the refugium baffle). I too was concerned but tested alright

Lenny_S · Oct 23, 2015

90 degree elbows aren't a whole lot better than two 45 degree elbows as far as increasing head pressure. Increased head pressure is really the only drawback in having bends, unfortunately for most they are unavailable. There are formulas to figure out the exact amount of head pressure but an easy rule of thumb for 1" pipe is to add 8" of head pressure for each 90 degree elbow and add 3" of head pressure for each 45 degree elbow. As you can see, there is only 2" of head pressure savings using two 45's rather than one 90.
In your case you should add 32" of head pressure for your 4 elbows to the actual height above the pump to get the total head pressure. Then just size the pump to the flow rate you want at that head pressure.

pdiehm · Oct 23, 2015

The plan is to get a deep water aquatics bldc 8 or 10 during Black Friday sales. I am not overly adept at making an efficient return line given how it is set up, so I will get a larger pump than the Sicce 5, which currently has my gate valve about 7/8 closed. I was amazed at how little the opening was for water to flow through.

Lenny_S · Oct 23, 2015

lemonyx said:
Use 2 45's elbows to soften the corner. My concern is when it's running and the return is turned off , how much room do you have for the water that drains back?

In that tank if it operates at 10" of water, that will leave 6" of space or 16 gallons for back siphoning. As long as the return lines and overflow aren't too deep, that should be ok. I always recommend you simulate a power outage or return pump failure in a controlled test and not assume you have the excess capacity to handle that.

Lenny_S · Oct 23, 2015

How big is your tank?

pdiehm · Oct 23, 2015

120 with a 40 breeder sump

lemonyx · Oct 23, 2015

With that size sump and plumbing, no more that a mag 5 or 7

If you really want to eliminate pressure you can use a pc of spa flex and have it curve up, but your using 1/2" ? PVC so not too much flow there

pdiehm · Oct 23, 2015

1" bulkhead. 1.5" drains. And as mentioned with the Sicce 5.0 the gate valve on main siphon is about 1.5 turns from being fully closed

Lenny_S · Oct 23, 2015

pdiehm said:
1" bulkhead. 1.5" drains. And as mentioned with the Sicce 5.0 the gate valve on main siphon is about 1.5 turns from being fully closed

Hmmmm... I agree with lemonyx on the pump. That Sicce 5 is actually already plenty. I have a 160 gallon tank and run a quiet one pro 5000 (roughly the same as the Sicce 5) and I have 800 GPH (calculated) from the pump. I only dial back my 1.5" drain line to reduce noise. But my return is 1", if yours is only 1/2" that is way too small, and that's your problem. Spend the money on redoing the return plumbing and keep the Sicce. That pump will give you more than 5x tank volume per hour turnover. That is plenty for filtration, then to increase flow use a wave maker or a strong power head or two in the DT.
I think a lot of folks hear about that 30-50 times tank volume turnover and think that means from the return pump, but that isn't the case. Even the 10-12 times tank volume for the return is no longer considered appropriate by most experts. 3-8 times tank volume is now the generally accepted rate.

Harold Green · Oct 23, 2015

I have about six times tank volume return flow and it's more than enough to filter the tank water clean in less than an hour from a heavy feeding of phyto or other coral foods. I agree the best way to increase flow is to increase line size. Certainly no smaller than 3/4". I noticed in your picture what looks like a standard plumbing union. Most neck the line size down quite a bit. You can find ones online that are open for a better flow than the standard ones. Mine came from amazon(spears 497). You can also go with a size or two larger unions and reduce them down to the size pipe you're using. Your finished system should flow full volume on the pump and be sized to match the drain lines after figuring head height. Simply put drain flow equals pump flow at head height. You should not have to throttle either or you're wasting power.

pdiehm · Oct 23, 2015

My return piping is 1". I absolutely need to close down the siphon line because if I don't, the Sicce can't keep up with the drain (1" bulkhead and 1.5 drain pipes).

My concern is, even with the fuge line closed off, I still need to close that drown valve almost fully. I imagine once I open the fuge line a little, I will have to close the siphon valve further.

I think that is why I was thinking of going to a stronger return pump.

I can also redo the return line to eliminate some of the 90's and just use vinyl tubing from the fuge T to the top of the return over the tank edge.

It's my first go through at a build and I have done about 1,000 things that I would do differently now.

Lenny_S · Oct 23, 2015

pdiehm said:
My return piping is 1". I absolutely need to close down the siphon line because if I don't, the Sicce can't keep up with the drain (1" bulkhead and 1.5 drain pipes).

My concern is, even with the fuge line closed off, I still need to close that drown valve almost fully. I imagine once I open the fuge line a little, I will have to close the siphon valve further.

I think that is why I was thinking of going to a stronger return pump.

I can also redo the return line to eliminate some of the 90's and just use vinyl tubing from the fuge T to the top of the return over the tank edge.

It's my first go through at a build and I have done about 1,000 things that I would do differently now.

The thing is, the drain will usually always match the volume of the return in a continuous circuit up to the maximum volume of the drain. So if your drain can handle a maximum of say 1500 GPH (most 1.5" drains) then any volume the pump puts out that is less than that will get matched by the drain "automatically ". It is actually quite risky to throttle back the drain as much as you are because if the pump is running and the drain is too slow you'll empty your sump into the tank, probably overflow it, and allow the pump to run dry and perhaps damage it.
The way to set this all up is to let the tank fill just to the start of the overflow. Then fill your sump to the running level you want (in your case 10" or just over your baffle). Then let the pump and drain run wide open, the sump will empty some. But you just keep adding water to the sump until it is back to the running level you want. The level in the tank will remain constant and can only be adjusted from the height of the overflow (if you have one that can be adjusted). The height of the water in the sump is what will fluctuate and that's where you'll top off.
If it doesn't work this way, something is wrong and you should figure it out ASAP.

pdiehm · Oct 23, 2015

THe problem with opening my main siphon line (we all know a siphon can drain water, a lot faster than a regular stand pipe). My tank is not reef ready, I drilled it for a beananimal overflow system. With 1" bulkheads, and 1.5" pvc pipe, my drain can handle roughly 2,000 gph. My sicce 5.0 return pump, can only push about 900 or so (give or take) gph back to the tank. If I open my gate valve on the siphon drain, it will drain the overflow box faster than the Sicce return pump can pump the water back to the tank, and the siphon will break, and my alarm for an elevated sump water level will go off and the drain becomes extremely noisy since it's sucking air.

The way it is balanced out is to adjust the gate valve on the main siphon until there's a slight trickle of water going down the open standpipe drain, but for this balance to occur, the gate valve is about 7/8 of the way closed. This keeps the water level constant in the tank, the overflow box, and the sump.

There's nothing wrong with how I set it up, the main issue is, if I want to open up the siphon line more, I need to get a return pump that can match what my drain is doing. the old thinking is that a 1" bulkhead can handle ~800gph. While that's true, you add a siphon to that, and that number doubles. Easily. Add in about 30" of gravity pulling the water down, and it's approximately 4,700 gph.

Here's a calculator:

Inside pipe diameter of a 1.5" PVC pipe is about 1.590"
My head drop is approximately 30"

Using the submerged discharge option gives you that calculation. http://www.beananimal.com/media/6840/flowcalc.swf

Another option, and one that I'm not particularly fond of is to change my siphon drain plumbing to 1" instead of 1.5".

Lenny_S · Oct 23, 2015

Ok, I have the complete picture now. Since you should have the emergency stand pipe with that system, then size the pump as big as you like. But 900 GPH is more than enough filtration for a 125 so keeping as is would work.