Sump design, baffle placement and height

[AlanM]

I was posting on someone else's thread about glass baffles and ended up wanting to ask a bit of advice about my own sump, so a new thread seems appropriate.

 

I have a 40 breeder that I drilled in the bottom in the corner and put a 1.5" bulkhead in. I have the three drain pipes from a BeanAnimal config going in at the opposite short end and ending 11" from the tank bottom. BeanAnimal says that they should always be below the water line, but only by 0.75" to 1". So that means 12" baffle around those drain lines at least or else extending them with a coupler. I cut them that high when i had some baffles held in with weatherstripping, but they let go.

 

My original plan was to put a bubble trap under/over pair of baffles about 10 inches from the drain end and put my cs1 in there. That would be a 12 inch water height for cs1, but it can supposedly handle that. Then i would just leave the rest open with a bucket in it for a fuge or maybe put another pair of baffles near the drain for a big fuge section.

 

My questions are, does the cs1 work ok in 12 inches of water in folks experience? Would I be better off just setting the level that high around the drains using an L shaped baffle and put the cs1 and any other reactors just in the restof the sump?

 

I guess I'm wondering if the easy way I was thinking about doing it is wrong for reasons that will only beome apparent to me with time.

[Origami]

I'm having trouble visualizing this. Can you just set the CS1 up on a stand, Alan, to raise it off of the bottom of the sump? As long as you have the head room above the sump to accommodate the raised skimmer, this is one way of adjusting the amount of water that the sump sits in.

[AlanM]

You're right.  I forgot about putting it in a stand.  That should work for the skimmer.

 

I guess what I'm looking for is advice from people who have run them for a while for sump mistakes.  There are a few things I've thought about already.

 

I'm wondering if I'm going to run into trouble with things like, for instance, an ATO sensing in such a large body of water, meaning the entire rest of the 40g breeder with an 18x26 inch footprint.  I tested out the Avast Deluxe ATO, and it doesn't seem to kick on unless I move it up by around an inch.  That's 2 gallons of evaporation over an 18x26 footprint before it kicks on.  Maybe there are problems with the ATO, or maybe there's a time delay built in, but that seems like a lot of evap before replacement with a 100g total system.  Or maybe I need another baffle near my drain from the sump that would let the ATO sensor be on a much smaller compartment of water.  

 

But then what if that volume is too small so that it makes startup impossible because the volume of my return line and drain lines will be larger than that small compartment of water volume so the water won't start flowing through the sump before that compartment is empty.

 

Or if I've made a mistake setting the water level so high with 12 inches at the first baffle because it will end up being a tremendous amount of pressure trying to push the baffles out of the way if I want to set the second baffle at 6 or 8  inches in order to keep the sump volume down to account for backflow in power outages.

 

So it's things like that which maybe people who have owned lots of sumps before would know that I don't.

Edited July 10, 2013 by AlanM

[Origami]

Rob (Zygote2k) has a lot of experience with the CS1 in both his old home setup and in some of maintenance tanks. If he doesn't chime in here, send him a PM to point him to this discussion.

 

If you put a baffle in before your return pump, thereby reducing your return chamber's volume, then that's the chamber where the effects of evaporation will be seen first. Still controlling your salinity to with +/-1% (which is what 2 gallons is, +/-1 gallon) is very good.

 

My Avast ATO keeps the water level within about 1/2 or so, maybe 3/4 inch on the outside.

 

Remember, the water in your return lines will for the most part flow back into your sump, filling it typically over the final baffle. Pressure can be an issue if you don't seal the baffle in well. I've had no trouble installing even acrylic baffles into glass sumps using silicone. Silicone's not known for sticking really well to acrylic, but it sticks well to glass. If you run two good beads on either side of the baffle, it holds it in place well and keeps it sealed. Twelve inches of water hardly constitutes a lot of pressure. Remember 32' of water equals about 14.7 psi, so 1 foot of water is less than 0.5 psi. On a 12 inch baffle that is, say 15 inches wide, that's 90 pounds distributed across close to 40 inches of sealed edge. That's means the silicone is dealing with about 2 pounds of pressure per linear inch (roughly speaking). The acrylic will more than stand up to 0.5 psi.

[matt]

K.I.S.S. ...not that the last "S" applies to you.

 

The lower the flow through the sump...the easier it is to keep bubbles from returning to the display. They bubble up before being swept forward by currents while still rising.

 

Small return area is relative...but I would go on the small side for ATO sensitvity. However, calculate your return/drain lines and go from there. If you're worried about draining the return section upon start-up...then initially let the overall water level in the sump be above the single baffle separating the return section. As the water starts pumping you'll see how much more water you can remove from the system so that each compartment has it's own water level when the return pump is on. Just try to keep the skimmer cup out of the water at all times...pre- and post-activation of the return pump.

 

Get yourself in the right ballpark with the sump baffle heights and don't be afraid to redo the plumbing, and pipe height, where you dump water into your sump. PVC is relatively cheap as this hobby goes.

 

Have you looked at Melev's website and his sump designs? Good place to start IMO

[AlanM]

Thanks for the advice guys.  I did look at Melev's site.  He has good info there.  I know the theory of how the sump works, I guess, but the devil seems to be in the details.

[TheyCallMeMr.703]

Yeha', I plan on turnin' my 3oGallon into a sump for my 55, Good info, and may need help from you'all If possible, Drinks and Food always provided of course, for the help.