sump/fuge design input

[kirby_32]

Looking for input on a sump/fuge design for a 75g rr tank.

The tank will be mostly soft coral and maybe a few LPS's, fish, and inverts.

The sump/fuge is a 40g tank. Plan to use 1/4" plexiglass for the dividers. Will have sand, live rock rubble, and cheato.

Questions:
1) Is the height difference between the sections enough? It drops 1" per section.

2) Was thinking of drilling a few holes in the divider right before the fuge to get some flow in the middle. Good idea or not?

3) Is 5" enough for a remote deep sand bed? Or should I go 6"?

4) For power loss surge capacity I figured 2" off the top of the 75g or 7.5g would be needed. Based on max water level in the sump/fuge I should have approx 9g available which should be good.

5) For auto top-off I plan to use a gravity fed system. Float valve connected to a fresh water reservoir. Good idea or not?

Any comment or suggestions would be appreciated.

 

[kirby_32]

bump

 

[Dave Dunbar]

Hello
Dont use Plexi for your baffles or use atleast 3/8 because the 1/4 will flex under pressure. I used it in only 10 inch of water and it flexed like crazy. get some 1/4 glass (cheaper anyway) and use it
Just my 2c
Dave

 

[Phong33]

Sounds good but I agree with Dave, go with 1/4" glass. Your local glass shop will cut it up for you. Pexi will not bond to the glass tank very well.

 

[jer77]

Glass baffles are the best way to go, like said before. They won't flex or bend and possibly detach itself.

1. Yes this should be good. Are you sure the skimmer will work well in 14'' of water or are you going to raise the skimmer?

2. This may be a good idea to get some flow through the fuge.

3. 5'' should be enough especially i you are using oolitic sand like aragamax.

4. Sounds good, just remember to allow for the back suction from the returns too.

5. I'm not to knowledgeable about this, but I know float valves are a great idea.

Just a few questions... Why is the return pump section so big if your going to have a float valve? You could increase the fuge area. Are you going to add teeth or eggcrate to the baffle after the fuge?

 

[sjm817]

Nice big sump. I would get rid of the bubble traps since they dont do anything to prevent bubbles anyway. Maybe make the fuge bigger and return section smaller. Plexi will bond well enough to glass for baffle use.

 

[kirby_32]

Thanks for the input.

Will look into local glass shops.

 

[kirby_32]

Missed a couple of replies when I sent mine.

The skimmer I'm going to use is the Urchin Pro. It indicates it does not need to be raised although I need to confirm putting it in this much water will be ok.

Didn't think of the egg crate but that is a good idea and will be added.

As far as the return section with the auto top-off it probably could be smaller. Actually thinking about it would be better since it will make the float more sensitive (smaller return area will have a larger drop in height with the same amount of evaporation vs larger return).

I'm going to look at glass for the baffles although I liked the idea of a few holes for middle flow. Maybe if cost is not too great can have some drilled in the glass.

Although I am new to SW this is the first recommendation I have seen to not use bubble traps. Are they really a waste of space and material?

Thanks again for the input.

 

[sjm817]

Yes, the bubble traps are a waste of space. Microbubbles will travel right through them since they are not buoyant enough to float up when the velocity of the water is carrying them through the trap. The O-U trap by your return is even worse since it forces the bubbles down low where they will get sucked into the return pump. Just simple dividers, keep the bubbles all the way to one end, return pump at the other end and let the bubble dissipate up to the surface.

You are correct that a smaller return will make the float more sensitive which will topoff smaller amounts more frequently which is especially good if you are topping off with Limewater.

 

[Shagsbeard]

You really don't need the first bubble trap... I'd have just a single layer there. You also don't need 1/4" glass, as it's supported on both sides. 1/8" glass is fine for this application. I doubt you really need any trap at all in this system... but if you want one, put it in the area just before your return.

An auto-top off makes the return area stay at constant depth, so there's really no reason to make your return area that big. It should be big in a system that doesn't have auto-top off, but since you're going to, I'd make that area much smaller, and give the refugium more space. You could build a frag station in it if you're looking for a use for the space.

 

[NeveSSL]

Correct me if I'm wrong, but your water in the baffles will only be as high as the lowest baffle.

Also, I personally think bubble traps do help. Maybe not a ton, but I can watch bubbles in one side of my trap rise up and pop and not go to the other side. Just my experience, though.

Brandon

 

[WinnipegDragon]

If this is going into a standard 75g stand (48x18) you do realize that there is no way you will fit a 48" long sump in there, right?

 

[afelder]

I would switch the refuge with the return area and have the drain split to flow into both skimmer and fuge area. I would use a powered setup for you ATO simply because gravity feeds can cause overflow and salinity problems (I paid the $180 for the Tunze just because of all the redundant backups). :rolleye1: The last thing is make sure you have enough volume in your sump that if power dies it can hold the extra water to prevent floods.

 

[kirby_32]

Thanks for all the input. Good discussion.

For the stand, I am making mine own. The sump would not have fit in the standard stand and I also wanted it taller.

I like the idea of making the fuge area bigger with a potential frag station.

NeveSSL- not sure i understand what you are saying. Since each section has a baffle that goes to the bottom, each section can have its own height. I wanted some height difference to allow the water to cascade some to help with aeration and mixing. Although based on other comments may only do that on the baffle between the intake and the fuge.

I really wanted to avoid using power on the auto top off. What is the issue with float valves failing that could also be seen with power ATO units? Have there been a number of failures with the float valves? Anyone else using a gravity feed ATO? Would I need to put two float switches in series?

I believe I have accounted for enough volume for power failures.

 

[NeveSSL]

Nevermind... I'm a dunce.

Brandon

 

[Phong33]

<a href=showthread.php?s=&postid=10223924#post10223924 target=_blank>Originally posted</a> by Shagsbeard
You also don't need 1/4" glass, as it's supported on both sides. 1/8" glass is fine for this application.

Very glad my mistake was corrected. I used 1/8" glass on all my sumps and they work perfectly. 1/4" will be a waste of money.

 

[kirby_32]

Anyone using a gravity fed ATO system that includes a float valve for control care to share their experience?