whare do I put my float valve?

[StirCrazy]

ok here is a pic of my sump


which chamber would I put the top up float valve? and are there any other conciderations I should look at with this sump?

Steve

[ 19 March 2002, 23:08: Message edited by: StirCrazy ]

[Kenzy]

Put it in the last chamber with your return pump. If you're using a Kent type float valve mount it as high as you can on the last baffle. This will reduce the amount of bubbles being made as the water flows over the baffle, less of a drop equals less bubbles. Something I learned after the fact. :rolleyes:

[Canadian Man]

steve
if the sump is to scale than you dont have alot of room for error with your water level in the sump, especially in the last chamber. the only other concern i would have is your refugium is only as deep as the height of the baffles but this is the way you might have desinged it so i just thought i would point that out .
cheers
Jonathan

[DJ88]

If your baffles are set up as you have drawn them steve you are flirting with a burnt out return pump. You want to maximize the water you have in that last area so that if water levels do fluctuate for any reason you don't run your return pump dry. For my mag 18 I am running an area that is 12x12x12. Even then I may run into trouble.

As well if you have your water level that low and you have a sand bed you are going to have a fast current running over the sand bed.

Say the baffles are 6 inches high and you try to put a 4" sandbed in there so it functions as a DSB. That leaves only 2" for water to flow over. And the shallower the depth the faster the water will move. As well it will create currents and will move the sand into your baffles then the pump. killing it. for example, I am looking at 6 inches minimum of water depth from the DSB to the waters surface. You want as slow a flow over the 'fuge as possible to maximize nutrient removal and filtration. as you have it now it will be a fast river flowing over your sand.

You may want to move the height of the baffles up to about 4-5 inches below the top of your sump. That is a general number. Mine are 6. that gives me about 15 extra gallons of H20 I can let flow from the tank to the sump if the power goes out.

Just my .02.

[Canadian]

Darren, you have to keep in mind that Steve doesn't have an overflow box in his tank so he also has to ensure that his sump will be able to accomodate the water in the pipe and whatever will back syphon from the main tank. I'll assume Steve has taken the necessary precautions to limit back syphoning and so on.

But I do agree that it would be preferable to have the baffles quite a bit higher to ensure decent water volume in the sump. Otherwise it's going to necessitate a very precise top off system and a large reservoir of top off water.

Oh, and regardless of how tall the baffles are I'd put the float valve in the last chamber because that's the only place it's going to work. With those baffles set up the way they are the only place there is going to be any fluctuation of water volume is in the last chamber.

[ 20 March 2002, 14:54: Message edited by: Canadian ]

[DJ88]

Ahh I forgot there is no overflow box to limit the amount of water going in. Hmm gonna be tricky. I forsee some floods. or darned near close.

You are going to be dancing on a fine line between burning out your pump and flooding steve. IMO. How big is your sump?

And as well since I forgot to add it. Put your float valve in the last chamber. It is going to exhibit the change due to evaporation.

If your baffles are less than 6 inches high I would not put any sand in your fuge area. It will get pulled downstream like a river and into your pump. This is more than likely going to turn into a high current area depending on the size of your return pump. If you make it a low flow sump you can do the sand bed. High flow and it will be a dust storm. Just so you know.

[ 20 March 2002, 16:30: Message edited by: DJ88 ]

[StirCrazy]

ahh ok I see a bit of confusion due to my drawing LOL. ok the hight for thebakkels is not se yet :D the sump tank is a 33gal tank. (I was planning on picking your brains on sump design at the meeting) I was thinking that it should go in the last chamber my self also bu then I also was wondering if I should run the water level higher then the baffels or let the baffels determan the running water hight? when I set up the tank I plan on filling everthing to a working level with the pump off, then adding water to the sump till I get my hight I want to have as a max when the power goes out. then I will start the system up. I was thinking ofhaving the water level about 12" deep in the sump when everything is running.

Steve

[DJ88]

First question. How far below the waters surface is your spraybar "overflow"?

For example if it is six inches below the surface you will need to be able to hold approx 20 gallons in your sump as this much water will flow back into your sump if the power goes out due to siphoning from your main tank. This means you will only be able to have 10 gallons of water in your sump.

48" * 18" * 6" = 5184/231 = 22.44 gallons draining to your sump in event of a powerfailure.

33g - 22.44g = 10.56g gallons max allowable in your sump so you don't overflow when the 22.44 gallons returns to the sump.

10.56g * 231 = 2439.39/36" = 67.76/12" = 5.65" max allowable water depth in sump. So your baffles can't be any higher than 5". If they are higher your sump will overflow when the power goes out. If you put the lower baffles at 5" high then make the area of the sump where the retun pump feeds from 12" long, you will have 12" * 12" * 5" = 720 720/231 = 3 gallons of water for your pump to work from. If you concider that the pump will be about 2 inches above the bottom of the glass you will only have an actual 12" * 12" * 4" = 576/231 = 2.49 gallons of water for the pump.

That is not a lot of water.

The only way you will be able to use the 33 as a sump with your tank is if you have the tank drain in and get rid of the second set of baffles and make the right hand 2/3rd's of the tank as the drain area. You will not be able to have a fuge in your 33. The flow will be too fast and too shallow.

IMO

If you were to have the depth of your sump at 12 inches, in the minutes after the power goes out you will have 11.88 gallons of water overflow into your stand.

12" * 12" * 36" = 5184/231= 22.4 gallons of water in the sump. With the previous calculations I made an the spray bar is 6" below the waters surface you had 22.44gallons drain into the sump. this makes, 22.44g + 22.44G= 44.88Gallons into your sump. The sump only holds 33 so..

44.88g - 33g = 11.88 gallons overflowing Everytime you lose power.

All these calculations are not taking into account the volume taken up by gear/glass in the sump. Keep that in mind. More space taken up means more water going outside the sump.

Either you are going to want a much larger sump or else have your spray bar an inch or two below the surface of the water(if not closer). This is why overflow boxes are used. They limit the amount of water draining into your sump by having bottom of the teeth 1/4 - 1/2 inch below the surface of the water. By drilling anti-siphon holes in your return lines at this same depth you will have a very minimal amount of water draining into your sump.

Hope that helps.

[smokinreefer]

sorry, i skimmed through darrens post cuz its just too long! [img]tongue.gif[/img]

but as for the burning hte pump out part...youll probably want the last baffle as high as you can.
that will minimize the chance of bubbles getting into the return and also minimize the room for error in runnning your return dry.

FWIW, on my poorly designed sump, my float valve is only 5" off the bottom...and if i have a near empty top off bucket before i go to work, my returns will be sucking air. keep in mind YMMV as i have a large system with alot of evaporation. **although i will be using a much larger topoff resevoir soon, i am still gonna rais ethe level of my float valve by a bout 4 more inches.

so my suggestion is to raise the level of water in the last chamber as high as you can accomodate without the potential for a flood.

HTH [img]smile.gif[/img]

[StirCrazy]

hmm ok I plan on running the spray bar so parrt of it is above the water level. (I will drill more holes if nessasary to achieve this as I want it to surface skim). so in theroy only one inch of water should drain down if I made my spray bar right.

my tank voume is about 3.83gal / inch of hight so at the most I want to have 2" drain down and what ever is in the lines (say another 2 gal.

I guess calling the middle chamber a fuge is kinda wrong.. it is more of a place to put extra rock (don't need sand there as the real fuge will be a 20 gal ontop of the stand)

I will be drilling anti-siphon holes in my return lines just under the working level of the tank (maby 1/4 to 1/2 a inch is what I planned on)

do you think I should just make it a two chamber? have the first foot for everthing to workout of and the last two feet as he working area for the pump and top up? after all there is the 25 gal tank to put rock in also.. if this is the prefered method how should I do the baffels (how hight and how many)? I want to ensure that all the bubbles I can get out are got [img]smile.gif[/img]

Steve