Fishy!'s Long and Low 60ish Gallon

[Myka]

Sounds like a sweet tank! I'd suggest a single return line for a tank that size. My tank is similar dimensions and I have one return.

I'd plumb the frag tank to the main system for stable parameters plus the frag tank will match the display so no shock when you move stuff.

[Fishy!]

Thanks Myka! I am quite excited for this new addition.

Originally Posted by Myka

Sounds like a sweet tank! I'd suggest a single return line for a tank that size. My tank is similar dimensions and I have one return.

A single return for the display or frag tank? What is the advantage of having only one return? I will be using a dc return pump so i can easily adjust flow via the controller.

Originally Posted by Myka

I'd plumb the frag tank to the main system for stable parameters plus the frag tank will match the display so no shock when you move stuff.

I am of the same mindset. I have always been of the thinking that more water volume = better. Im sure few people would refute that. The only concern i have is in the event of a tank crash, you are going to lose everything, including any possible "insurance" frags you may have. This is my biggest concern with plumbing it in. Also will be dependent on if there is room inside the stand for the frag tank. There is no room outside the stand for this to be plumbed in.

[Myka]

Originally Posted by Fishy!

A single return for the display or frag tank? What is the advantage of having only one return? I will be using a dc return pump so i can easily adjust flow via the controller.

On the contrary, what is the advantage of having two returns in a small tank? I see no advantage to having two return lines on a tank less than 6 feet long, and having only one return line means simpler plumbing and more room under the stand. My system is 92 gallons gross, and my return pump is 400 gph after head loss (not including loss from pipe and fittings). I'm not sure why a person would want to split 400 gph. I could probably pee harder than that. Hehe.

How much volume do you plan to push through the sump? Your tank is 61 gallons gross, and the sump probably won't hold 20 gallons. So you're like 80 gallons max. I wouldn't push more than 400 gph through your sump, that's 5x turnover.

Originally Posted by Fishy!

The only concern i have is in the event of a tank crash, you are going to lose everything, including any possible "insurance" frags you may have.

Yeah, that's a good point. I always make sure my favorite frags are also in friends' tanks.

[Fishy!]

Originally Posted by Myka

I'm not sure why a person would want to split 400 gph. I could probably pee harder than that. Hehe.

Good point. I had not thought of it like this. I was hoping to have a net 600 gph going through the sump. I guess it's just a matter of aesthetics for me. Where would I place a single return on a solid back wall? Maybe in the middle, with the two powerhead in each corner. Something to think about.

Originally Posted by Myka

How much volume do you plan to push through the sump? Your tank is 61 gallons gross, and the sump probably won't hold 20 gallons. So you're like 80 gallons max. I wouldn't push more than 400 gph through your sump, that's 5x turnover.

Tank with overflow is 69 gallons. I was hoping to have 20-30 gals of water in the sump ideally netting out at 100 gallons. I will have to be careful to leave enough to back siphon room in the sump for approx 5 gals. (40" tank width X 4" overflow depth X 6" height of full siphon below water level). That doesn't account for any back siphon of return lines or the volume of water held in the actual plumbing. I'm afraid I will need a pretty tall sump. This might exclude me from any pre-manufactured sumps out there. Thoughts?

Thanks for your feedback. Keep it coming.

[Myka]

Originally Posted by Fishy!

Good point. I had not thought of it like this. I was hoping to have a net 600 gph going through the sump. I guess it's just a matter of aesthetics for me. Where would I place a single return on a solid back wall? Maybe in the middle, with the two powerhead in each corner. Something to think about.

For mine, the drains are where your returns are, and the return is in the middle. You could just keep the layout how it is, and pick one side or the other for the return.

Originally Posted by Fishy!

Tank with overflow is 69 gallons. I was hoping to have 20-30 gals of water in the sump ideally netting out at 100 gallons. I will have to be careful to leave enough to back siphon room in the sump for approx 5 gals. (40" tank width X 4" overflow depth X 6" height of full siphon below water level). That doesn't account for any back siphon of return lines or the volume of water held in the actual plumbing. I'm afraid I will need a pretty tall sump. This might exclude me from any pre-manufactured sumps out there. Thoughts?

Thanks for your feedback. Keep it coming.

I don't know what the heck I did to typo the tank volume, since I just redid it and can't come up with 61 gallons again.

The main drain in the back chamber (the one with the gate valve on it) has a standpipe on it which is 2" lower than the emergency drain. When the system is turned off it only drains a little over 1 gallon down to the sump.

However, I did design my sump to hold the entire back chamber volume which is 11 gallons (at operating level). My sump is 24 x 20 x 16", but there is an RO chamber along one side so the actual sump area is 20 x 19.5 x 16" which is 26 gallons if it's full to 15.5" (minus glass widths of baffles and such). With the tank running, the water in the sump is 8.5" deep which is 14.5 gallons. Add that 14.5 gallons to the 11 gallons in the back chamber (should it ever fully drain to the sump) and you have 25.5 gallons which fills the sump to 15". This sounds ok, but then there's the backflow from the tank/piping and the volume from the skimmer when it's off...

After all this planned redundancy though, I did my calculations with the back chamber being 3" wide (which is what I ordered), and I was surprised when the tank arrived with a 3.75" wide back chamber and my sump was already built. So, my sump won't hold the backflow from the tank/piping, the backflow from the reactors/skimmer/etc because the back chamber holds 2 gallons more than planned. If the back chamber was 3" as planned, then it would have all worked out.

You just have to plug numbers into an aquarium volume calculator and figure out how big your sump needs to be. Don't forget to take glass thickness into consideration. You need the inside measurements. Also, I don't know the water depth for the skimmer you picked. I made sure the skimmers I bought didn't need deep water. Some need 11" deep water, and I just didn't want that extra volume down there.

[Myka]

I'm waiting for paint to dry, so I did some rough calculations for you...

Assuming the actual dimensions of your back chamber is 39.5" long and 3.75" wide, and assuming the operating depth is 15", then you'll need just under 10 gallons of space in your sump, plus the volume your tank will drain (if it drains an inch that's a little over 3 gallons) and pipes/skimmer (shouldn't be more than 2-3 gallons), etc. So you need a total of about 16 gallons of empty space in the sump for full redundancy. If your sump is say 22" wide and you need say 9" depth in the sump, then if your sump is 24" long it will have 21 gallons in operating volume, add to that your 16 gallons, and if it's 16" deep (15" to be safe) you're probably going to overflow. If you made the sump 30 x 18 x 16" your operating volume would be 21 gallons, and total volume would be 35 gallons (to 15" depth). 21 + 16 = 37 gallons. That won't work either (for full redundancy). Play around with the numbers and you'll figure something out. Don't forget to consider the frag tank too. That'll throw a wrench in it.

36 x 18 x 16" total volume (to 15" height) is 41 gallons. Running volume at 9" depth is 24 gallons. Add 16 gallons to 24 is 40 gallons. Too close for comfort, and certainly won't work with your frag tank.

36 x 22 x 16" total volume (to 15" height) is 50 gallons. Running volume at 9" depth is 30 gallons. Add 16 gallons to 30 is 46 gallons. That gives you 4 gallons of "insurance" space.

36 x 22 x 17" total volume (to 16" height) is 53 gallons. Running volume at 9" depth is 30 gallons. Add 16 gallons to 30 is 46 gallons. That gives you another 3 more gallons of space, 7 gallons total. That's probably enough for your frag tank too depending how you plumb it.

[Fishy!]

Originally Posted by Myka

I'm waiting for paint to dry, so I did some rough calculations for you...

Assuming the actual dimensions of your back chamber is 39.5" long and 3.75" wide, and assuming the operating depth is 15", then you'll need just under 10 gallons of space in your sump, plus the volume your tank will drain (if it drains an inch that's a little over 3 gallons) and pipes/skimmer (shouldn't be more than 2-3 gallons), etc. So you need a total of about 16 gallons of empty space in the sump for full redundancy. If your sump is say 22" wide and you need say 9" depth in the sump, then if your sump is 24" long it will have 21 gallons in operating volume, add to that your 16 gallons, and if it's 16" deep (15" to be safe) you're probably going to overflow. If you made the sump 30 x 18 x 16" your operating volume would be 21 gallons, and total volume would be 35 gallons (to 15" depth). 21 + 16 = 37 gallons. That won't work either (for full redundancy). Play around with the numbers and you'll figure something out. Don't forget to consider the frag tank too. That'll throw a wrench in it.

36 x 18 x 16" total volume (to 15" height) is 41 gallons. Running volume at 9" depth is 24 gallons. Add 16 gallons to 24 is 40 gallons. Too close for comfort, and certainly won't work with your frag tank.

36 x 22 x 16" total volume (to 15" height) is 50 gallons. Running volume at 9" depth is 30 gallons. Add 16 gallons to 30 is 46 gallons. Hey, that might work...

Thanks Myka
This will definitely take a pad of paper and some time to figure out. The frag tank also throws another level of complexity to the equations. Any idea where a guy can find a chart with standard tank dimensions?

[Fishy!]

Originally Posted by Myka

36 x 22 x 16" total volume (to 15" height) is 50 gallons. Running volume at 9" depth is 30 gallons. Add 16 gallons to 30 is 46 gallons. That gives you 4 gallons of "insurance" space.

36 x 22 x 17" total volume (to 16" height) is 53 gallons. Running volume at 9" depth is 30 gallons. Add 16 gallons to 30 is 46 gallons. That gives you another 3 more gallons of space, 7 gallons total. That's probably enough for your frag tank too depending how you plumb it.

The problem I see here is that the total stand dims is going to be 22" deep. I then have to accommodate for the material to make the stands structure which is likely 4.5". That only leaves me with approx 16" of space. This is going to have to be one tall sump!