Does my sump really need baffles?

[X-37B]

.25" drop in a chamber that is 12" X 18" is much less water than a .25" drop in a sump that is 60" X 18".

Return pump chambers in a proper sump are the only chamber where the water fluctuates.

True about 5 times more or so. But quality ato"s dont drop a 1/4" before they kick on. At least ime dosent.

 

[X-37B]

You need baffles. Who doesn't want baffles. Everyone has them. Baffles do important things like baffling.

Really! We dont need no stinking baffles! Its called the "baffling syndrome" lol.

 

[LadyTang2]

.25" drop in a chamber that is 12" X 18" is much less water than a .25" drop in a sump that is 60" X 18".

Return pump chambers in a proper sump are the only chamber where the water fluctuates.

I thought water levels change throughout the sump and therefore even if a level is higher or lower it moves at the same speed if you know what I mean, I could see if the water level only fluctuated in the return like you mentioned how that would make the ato more precise/water line move faster. I guess thats part of what I did not understand, how do you make a sump so that only the last return sections water level moves?

 

[LadyTang2]

DBL post, see above

 

[X-37B]

I thought water levels change throughout the sump and therefore even if a level is higher or lower it moves at the same speed if you know what I mean, I could see if the water level only fluctuated in the return like you mentioned how that would make the ato more precise/water line move faster. I guess thats part of what I did not understand, how do you make a sump so that only the last return sections water level moves?

Baffles in the return section is only where the waterline moves. This is a standard in factory made sumps.

 

[Timfish]

No, you don't need baffles. I run most of my systems with just basic, unlit sumps. You will get cryptic sponges growing in them that are essential for removing labile DOC (See de Goeij, 2008) Here's a video of the sump on my R2R build thread:


I would not use cheap plastic totes though. Saltwater will leach out the plasticizers making the plastic brittle and prone to crack.

 

[LadyTang2]

No, you don't need baffles. I run most of my systems with just basic, unlit sumps. You will get cryptic sponges growing in them that are essential for removing labile DOC (See de Goeij, 2008) Here's a video of the sump on my R2R build thread:


I would not use cheap plastic totes though. Saltwater will leach out the plasticizers making the plastic brittle and prone to crack.

So HDPE or acrylic are better choices then?

 

[LadyTang2]

Baffles in the return section is only where the waterline moves. This is a standard in factory made sumps.

If I build my own, how does the baffle leading to the return chamber need to be arranged to make it so that it is the only chamber where water fluctuates?

 

[X-37B]

If I build my own, how does the baffle leading to the return chamber need to be arranged to make it so that it is the only chamber where water fluctuates?

Just look at some pics of sumps. It is pretty easy once you see it. If you can go to lfs and check one out.

 

[sawdonkey]

To simplify, the salinity of a 40g aquarium wouldnt change much if the water level dropped by 1mm because the surface area is small however, if the surface changed by 1mm across a 175g aquarium, the results would be significant.

But aren’t the ratios more or less the same? One just has higher volumes. While the amount of water pumped by the ATO in the 175 gallon sump is more, the impact to salinity is generally the same...so I’d say the “results would not be significant.”

 

[madweazl]

But aren’t the ratios more or less the same? One just has higher volumes. While the amount of water pumped by the ATO in the 175 gallon sump is more, the impact to salinity is generally the same...so I’d say the “results would not be significant.”

I think most sumps hold roughly 20% the volume of the system and in that case, the overall effect is small but in this case, the sump has the same volume as the display.

 

[Hemmdog]

If I build my own, how does the baffle leading to the return chamber need to be arranged to make it so that it is the only chamber where water fluctuates?

Like this:

 

[Timfish]

So HDPE or acrylic are better choices then?

Acrylic or glass would be my vote. HDPE will get brittle over time although it's life expectancy does depend on how thick it is and the light it's exposed to.

 

[PhreeByrd]

If I build my own, how does the baffle leading to the return chamber need to be arranged to make it so that it is the only chamber where water fluctuates?

In most sumps, the water level throughout (or at least most of it) will drop some as water is removed. But the top of the last section will determine the minimum water level in all but the last (return) section. In Hemmdog's photo, for example, note that the last (green) baffle seals to the bottom of the sump so water must travel through the slots cut near the top of it. The bottom of those slots is the minimum water level in the main part of the sump. The last (return) section, though, could be completely emptied without affecting the rest of the sump. The final (clear) baffle serves only as separation. It won't affect the water level at all.

 

[LadyTang2]

Is this true: the water level can be lower but not higher in the last compartment (if it were higher it could flow back), since the pumps are in this section the water level here is almost always lower there right?

And one of the main advantages of this is that the water level will drop more quickly in that last compartment than in the others because it is smaller, right?

 

[X-37B]

Is this true: the water level can be lower but not higher in the last compartment (if it were higher it could flow back), since the pumps are in this section the water level here is almost always lower there right?

And one of the main advantages of this is that the water level will drop more quickly in that last compartment than in the others because it is smaller, right?

Correct.

 

[K7BMG]

Open sumps should not be an issue. IMO.

What is lacking in this thread is the comments of the other tools we have to implement on our systems. The equipment that renders sump levels of no concern so to speak.

water level in sumps to maintain a proper functioning skimmer is old school when there are recirculating skimmers. These skimmers have been proven to function better as well. See the BRS video series.

If you have a controller that monitors salinity (Consistently and accuratly) and it is set to control the ATO of your choice, is a far better way to go. When your salinity is below your target level the controler has it on, and obviously off of it gets above your target level.

There is no way we can keep control of how much water will evaporate day to day accuratly. I agree there is an average, that said, if you set up a dosing system to add X amount of water automaticly everyday IMO your gona have way more salinity swings.

My sump 150G rubbermaid trough, has no baffles curently, I reserve the right to add them later, and have a recirculating skimmer that sits on a shelf above it. I will set its operating level when I implement it. System is new and in its nitrogen cycle..
My return pump shut off float is in the DT, and operates in reverse, so if my water in the DT rises to high the pump shuts off. (HOPEFULLY)

I have a 3155 that will be set up in the sump attached to a 165G storrage tank of RO/DI. I will see how that works out in the future.
Again tank is new.

My theories have yet to be tested and proven, who knows I could wind up with 100g of water on the office floor, a burned up return pump, and a salinity of 1.000.

 

[PhreeByrd]

Is this true: the water level can be lower but not higher in the last compartment (if it were higher it could flow back), since the pumps are in this section the water level here is almost always lower there right?

Sort of. Your normal water level in the sump will be wherever you set it. It could be above the top of all of the baffles if you want it there. But yes, that means the return (last) compartment will freely share water with the rest of the sump until the water level drops below the last baffle. Under normal/typical operation, the water level between the return section and the section before it will be the same. If you pump out the sump without returning water to it from the system, the level in the return section will quickly drop while the rest of the sump remains at a higher level.

In the sump in the photo Hemmdog posted, the water level is intended to be kept within the height of the slots in the baffle before the return section. Those slots set the water height for the whole sump. An ATO system will actually monitor the water height for the whole sump except for the intake section.

 

[Larry L]

I think the reasoning behind early sumps was baffles were incorporated as bubble traps.

Right, which was way more important then because we also used to rely a lot on our return pumps for in-tank flow (before there were so many options for in-tank flow pumps), so people were pumping super high rates of flow through their sumps.

Almost all modern in-sump skimmers require a constant water height for the skimmer to sit in.

A lot of skimmers will do better in a constant water level, but a lot also have a pretty big range of depths where they work just fine (look for the BR video about skimmers and water depth sweet spots).

 

[Emerson]

I ran an open sump (20 gal long) for years with no problem about 10 years ago. The biggest benefit for baffles is making the chamber where you run a protein skimmer run a constant water height. This gives you predictable (mostly not overflowing) skimmer operation. It's not hard to take a basic tank, cut or have a glass manufacturer cut two or three plates to size, and silicon them in place. Granted, it's a little extra work; but do it once and you're done.