Lots Of Very Basic Sump Questions

[RipSlider]

Having thought that I had got the plumbing right for a freshwater trial run of my big tank right, only to be proved disasterously wrong ( yes, it really was one of those "wet and shouty moments. Steve Got wet, Mrs Steve shouted ( I mean really, just becuase the carpet is new, why is that an additional issue???)) , and also looking at setting up a sump for my freshwater tank, I thought that I should probably come here tail between legs and re-check my original sump idea's and make sure I was right.

1) Does a sump have to be directly below the tank?
<for my freshwater tank, I would like to drill into the garage and run pipes through the wall to a sump, totally hiding the hetaers, filters etc etc. However, the garage is only 7" lower than the floor of house. This would mean it is 27" below the base of the tank.>

2) How do I calculate the amount of space that I need in a sump? Is it, as I thought, that I just need to fill the sump up to the desired level and gravity and pumps will take care of the rest?

3) How do I calculate the space that I need to leave in the sump to factor in a powercut to the pumps. Is it just the volume of water that would be above the weir teeth + the piping?

4) How do I make them QUIET??? After a 26inch drop, the water is stupidly loud. Can I add baffles of some sort? Or some sort of slide down to the bottom?

5) who makes quiet return pumps?? I was told ehiem were quiet. It's lies, I tell you, lies!!

6) If I added shut off's from the pipe work to/from the main tank to the sump, and I didn't have a DSB in the sump, just the equipment, can I run my water changes from there instead. I.e, shut off the water, remove x gallons from the sump, replace x gallons, then re-open the taps? Or is it better to do from the main tank?

I won't say what my original thoughts were, but I don't THINK I was being stupid, but it seems I may have been.

Many thanks

Steve

 

[andywg]

1) Having the pipes go sideways as well as down is fine. If you have the sump hidden in another room, then you can have it as ugly and as large as you like!

2) Ideally you want the biggest sump you can get. the more volume in it, the better off you are. Again, being in a garage gives loads of advantages here.

3) There is an easy way to make sure you don't have too much water in the system. I always fill my suimped tanks fromt he display tank. It will over flow and then fill up the sump. Once the sump is pretty much full I stop filling. You now know that there is not too much water to flood your system.

There is a problem with getting the baffle heights right as you would in theory need to calculate how much water would be in the display as well as the display to drain. I have normally found that so long as the sump is in a fair proportion tot he tank (around 10 to 20% of volume at least) then allowing 4" from the highest baffle to the top of the sump allows good operation and flexibility. Others probably have better ways of calculating it.

4) To quieten down there are a nubmer of things. First is to use a durso standpipe. second is to have the drain around 1-3" under the water and I have found putting a bend on it at the very end helps as well.

5) I use eheims on all my current sumps and they are extremely quiet. however, if you want a good quiet pump, and you have a agarage, look at sequence pumps. These are ones that are hard plumbed into the return line and do not sit in the tank. Little Giant make one for less than £100 that gives 9,500LPH for less than £100. And it only requires 95W to run.

6) You couold easily do the water changes from the sump, though I usually find the sump doesn't have the volume I need, however my sump experience is still FW so I hae to worry about keeping the media wet and all. In a garage setup I would look at an auto top off unit as well. However, if the sump is large enough, I see no problem with water changing from there.

HTH

Andy

 

[SkiFletch]

1) Does a sump have to be directly below the tank?

Not at all, the sump just has to be at a different plane of altitude than the tank to benefit from gravity. Going horizontally through a wall and then down into the sump is fine.

2) How do I calculate the amount of space that I need in a sump? Is it, as I thought, that I just need to fill the sump up to the desired level and gravity and pumps will take care of the rest?

Sort of. This part of sump design is actually crucial for safety so I hope I can explain this well enough. If using a sump below the display as you are, water is pumped from the sump up to the main tank. This will raise the water level in the display above that of the overflow(s) and water starts cascading down into the sump. That water level increase is usually anywhwere between 0.5" to perhaps as much as 1 or 2 inches. The water overflows into your sump and passes through whatever chambers you design for it and then is pumped back up to the tank over and over. The water volume that remains in the tank is the key. I believe you have a 7' tank and I'll just assume its front to back footprint width is 2' for the sake of argument. So if the water level in the display tank raises 0.5" the tank volume now holds 1008 cubic inches more water than it did before. So then lets say you have a 5' x 1.5' footprint sump below. You would need to setup your baffles so that there is at least 1008 cubic centimeters of headroom in the sump to collect the extra overflow water when the pump is shutoff (I'd go for a little more ). So if the sump was designed so that the highest bubble wall or divider was 1 inch below its top it could absorb 1080 cubic inches of water and you'd be all set. You're basically calculating the extra water (length x width x height) in the display tank and then making sure that the sump has enough empty space in it (length x width x height) so as not to overflow when you shut it off.

The other safety measures you need to impliment are to add a check valve on the pump side of the plumbing, and also put 2 holes in your return tubing (from pump to display) right at the water line when no water is flowing. That way if power cuts out, you dont siphon-drain through that pipe below the level that your overflow is capable of.

3) How do I calculate the space that I need to leave in the sump to factor in a powercut to the pumps. Is it just the volume of water that would be above the weir teeth + the piping?

Exactly, I pretty much explained that above I think

4) How do I make them QUIET??? After a 26inch drop, the water is stupidly loud. Can I add baffles of some sort? Or some sort of slide down to the bottom?

Depends, where is the noise coming from? Is it a gurgling at your weir, or a gurgling at your sump?

5) who makes quiet return pumps?? I was told ehiem were quiet. It's lies, I tell you, lies!!

*shrug* I cant hear mine over the turbo-fans in my computer so I'm the wrong guy to ask

6) If I added shut off's from the pipe work to/from the main tank to the sump, and I didn't have a DSB in the sump, just the equipment, can I run my water changes from there instead. I.e, shut off the water, remove x gallons from the sump, replace x gallons, then re-open the taps? Or is it better to do from the main tank?

Actually doing waterchanges in the sump is the reccomended way to do it, thats how I do mine