Sump design questions

[that0neguy1126]

So I had my dad over yesterday helping me finish up a few things with the sump. Right now I have 2 100g Rubermaid Stock Tanks. The person who gave me the suggestion to go with these, stated they had 1 tank about 4" higher than the other. So I had built a stand our of 4x4's so one sits on the ground a little higher.

While I was talking with my dad about joining the 2 tanks, he asked why one was higher. It got me thinking, and I had no idea why.

The plan was to have the DT train into Stock Tank 1. in Stock Tank 1 (higher one), I would have macro algae, skimmer, sock filter. The water would drain into Stock Tank 2 (lower one), which would have phospate/carbon and the 2 return pumps.

Since the 2 Stock tanks will be joined by 3x 2" pvc, what is the reason on having 1 higher? with the 2 tanks joined together, the water level will be equal in both regardless of if one tank is higher than the other. I looked around online a little bit, and it seems everyone using 2 tanks for a sump has 1 of the lower than the other, yet I cant think of any good reason why.

 

[dvenson]

i believe it would be for the water flow so that tank 1 is at a constant for skimmers and equipment and your Fuge and gravity feeds tank 2 which is lower for your return area

 

[Wicked Color]

You can have them all at the same level, just depends on how they are connected.

 

[that0neguy1126]

i believe it would be for the water flow so that tank 1 is at a constant for skimmers and equipment and your Fuge and gravity feeds tank 2 which is lower for your return area

I was thinking that the flow would be the exact same as what I am pumping up to the DT. The what drains to the sumps would be equal to what was returned to the DT.

You can have them all at the same level, just depends on how they are connected.

How so? I would think regardless of how they are connected, the water will be at the same level in both.

 

[dworkman]

I think he meant water level.

The higher sump would always be at the level of the overflow, while the lower would fluctuate slightly with evap. If they were connected without a difference in height, then both would fluctuate.

But with that much surface area, and depending on your ATO, the fluctuation would be almost non-existant.

Knowing how deep those stock tanks are, you should be fine, but with the second being gravity fed, you'll have some bubbles that might get pumped back into your DT.

 

[Ryan@FRA]

if two tanks are connected at the bottom, under the water line, then no matter what, the water level will be the same in both. evap will affect both, they both will fluctuate. I cant see any reason to have one higher then the other. Now if one was "spilling into the other and not connected under the waterline, then the top tank would stay the same level and the bottom tank would fluctuate. Personally, i would rather have my refugium fluctuate then my equipment area. In sump skimmers will perform better at a steady water level.