Need some help to get my tank going!!!

[Anonymous]

http://home.att.net/~rstockman/overflow.htm

here look at this and note the area inside the external box on the drawing to right that houses the J tube.

this water level will be the same as the internal box's water level at rest.

 

[Anonymous]

what does this do if you leave it running? does it overflow the internal box?

 

[the Wizard]

OK good, I have seen these drawings before...they will be good to talk from, and in another hour or so I could photogragh and post this thing I've built (although now I'm a little sensitive about it....it WAS my work of art...haha).

Mine is very similar yet maybe significantly different.

First I notice this siphon is a U not a J, as mine is.

Next I have no standpipe, just the drain. I assumed if noise was not an issue this was OK. But maybe this has some function with regard to maintaining a water level.

Next, my interior box has holes in it so it always stays at the tank water level. I like the idea of skimming the top, and could plug the holes, but I thought the major point was that the spill wall sets or is balanced with the tank level and this appears to be the case in the drawing.

Here's the thing I see that I don't understand, and that may be important. I don't see how the water level can be lower in the interior box (as shown) than the exterior box at the point where the siphon ends? Seems like its siphoning uphill in these drawings?

 

[Anonymous]

OK good, I have seen these drawings before...they will be good to talk from, and in another hour or so I could photogragh and post this thing I've built (although now I'm a little sensitive about it....it WAS my work of art...haha).

Mine is very similar yet maybe significantly different.

First I notice this siphon is a U not a J, as mine is.

Next I have no standpipe, just the drain. I assumed if noise was not an issue this was OK. But maybe this has some function with regard to maintaining a water level.

Next, my interior box has holes in it so it always stays at the tank water level. I like the idea of skimming the top, and could plug the holes, but I thought the major point was that the spill wall sets or is balanced with the tank level and this appears to be the case in the drawing.

Here's the thing I see that I don't understand, and that may be important. I don't see how the water level can be lower in the interior box (as shown) than the exterior box at the point where the siphon ends? Seems like its siphoning uphill in these drawings?

the drawing appears that way because the area surrounding the outlet of the J tube (okay U :wink: ) is not shown on the left drawing.

i would really like to know if the interior box on yours overfills.

 

[Anonymous]

just looked at the pic and you are right. it does appear to flow uphill :lol:

 

[the Wizard]

My interior box is always exactly at the same water level as the rest of the tank, since there are many holes in the bottom. Actually I became concerned that these holes were too restrictive so just as an experiment I just ran the siphon from the main tank itself. Of course I have no occupants yet!

I'm home now so I'll work on that pic or two.[/quote]

 

[Anonymous]

my apologies for the lengthy problem solving but i think i can tell what is going on now. a pic is truly worth a thousand words.

looking back at the whole thread i would say your overflow works fine. if your tank doesn't overflow and you aren't at a higher level than you are targeting then your only problem is an empty exterior overflow box (and a bunch of holes in the interior one :lol: ). which isn't really a problem. if you want to increase flow through the tube joining the two boxes you need only go a size smaller, given it will keep up with the load.

as for the repeated question on the interior overflow box, my apologies again. you already told me it was full of holes, i am just not used to that.

so, let's see what we have been discussing

 

[the Wizard]

OK, well now I have pics...haha....now that you probably don't need them any more. Remember the flex tubes you see are just temporary so I could see the trapped air pocket.

Now that you understand it all...let me re-state the problem....the tank does overflow! I use a mag 18 return pump and I have to throttle it back to what seems like only 20-30% capacity so that it doesn't, and I'm sure that's not very good for the pump.

I need more flow from the tank, through the siphon, to the exterior tank. Any ideas?

 

[Anonymous]

first off, can resize those. they are a bit much :lol:

what is the diference between water levels between the exterior overflow box and the interior tank water.

 

[the Wizard]

HaHa...OK there you go....I haven't done that much board posting. Although my son does run cuda-challenger.com for the car guys. He helped me resize the pics.

If I run the pump throttled way back the spill wall height defines the tank water level as I designed. However, if I run the pump faster the water level in the tank raises to the point of over-flowing. This is even though the exterior system is working...it's just not working fast enough. And it's not the exit port that is full capacity...it's that the siphons need to move the water from the tank to the exterior box more quickly.

 

[68fj40]

If I can jump in. I noticed you said the interior and exterior boxes are the same depth. At least this is the impression I got. Idon't know if it matters but all the overflows I have used have an exterior box that is 3+inches deeper than the interior box. I don't believe you can get a strong siphon if the siphon tube is equal length on both sides of the tank.

Please ignore this if it has already been addressed.

 

[the Wizard]

Hi 68fj40,

All help is appreciated. Here's where I think we are with regard to your comment. If two containers have fluids at equal levels no matter how deep either one is, or how long the J tube is on either side, it will not move water. And I think that's what I have.....two containers with equal levels of water. Wouldn't help to deepen one, or lenghten a tube. Yes? No? Agree? Disagree?

 

[the Wizard]

Let me just ask this? What is the most I should expect to move through a 1" siphon pipe? Maybe there's just no way this thing could ever keep up with a Mag 18 with 4 feet of vertical.

 

[Anonymous]

Maybe there's just no way this thing could ever keep up with a Mag 18 with 4 feet of vertical.

which is one of the first concerns i brought up :wink:

i assume now you are only moving water from the sump to the main tank with one mag pump, right?
it is rated somewhere around 1800 gph and a couple 1" can be expected to do that if the head pressure at the discharge end is great enough...but you are pushing it.
a 1 inch discharged C-siphon is rated at 800 gph.

if the water is moving quickly through the J tube portion and the flooding of the aquarium remains i think you are in need of a larger J tube (diameter).

if it is moving sluggishly through the tube i think 68fj40 is on the right track. you need to modify that exterior box to accomadate a greater difference in elevation between water surfaces.

 

[68fj40]

Another thing I'm wondering about is the divider in the exterior box. I don't quite understand the use of it to control water level. Looking at my overflows on my tanks the divider is well below the heigth of the tanks water level. I would think if this divider is close to the tanks water level this would hinder the siphon effect.


As for capacity, I run an ampmaster 3000 pump. When I firt got it I used two overflowboxes with one inch drains. I eventually got this to work with the pump wide open. I now use a c-siphon 150 with a single inch and a half drain

 

[the Wizard]

OK guys...what's a C-siphon?

Yes...one Mag 18 returning the water.

I started with a 1" ID J tube on each overflow box. Then I went to two. Then I added a third at 3/4".....it's still not enough. A lot of water flows but not near enough...how many more can I add? Actually I don't have any more room.

And I thought we already determined that a difference in elevation makes no difference if the water levels are eqaul? I'd be happy to mod it but this doesn't work by my understanding.

68fj40 - In the designs I've seen this divider sets the water level in the main tank. Do you have any drawings of yours, because I agree that if it can all be worked out a greater difference in height should flow more water. But I don't see how to do it.

 

[Anonymous]

OK guys...what's a C-siphon?

its a brand of overflow built by CPR.

Yes...one Mag 18 returning the water.

I started with a 1" ID J tube on each overflow box. Then I went to two. Then I added a third at 3/4".....it's still not enough. A lot of water flows but not near enough...how many more can I add? Actually I don't have any more room.

ok, earlier i though you were adding these to the under side of the overflow. i don't think adding more will solve your problem

And I thought we already determined that a difference in elevation makes no difference if the water levels are eqaul?

i will agree there, but your water levels are equal because your box is built that way. if you lowered the exterior box than the area inside it with the divider would set a lower water level elevation for the water inside that divider.

I'd be happy to mod it but this doesn't work by my understanding.

68fj40 - In the designs I've seen this divider sets the water level in the main tank. Do you have any drawings of yours, because I agree that if it can all be worked out a greater difference in height should flow more water. But I don't see how to do it.

if your skimmer box was not full of holes it would set the aquarium water level.

i am sure that 68fj40 will snap a pic for you. he won't be on until this evening though.

 

[the Wizard]

ok, earlier i though you were adding these to the under side of the overflow. i don't think adding more will solve your problem

No, not the underside. The problem has been getting the siphon to flow faster, so I added more area to the siphon, and it did work, sped it up a lot, just not near enough.

i will agree there, but your water levels are equal because your box is built that way. if you lowered the exterior box than the area inside it with the divider would set a lower water level elevation for the water inside that divider.

Yeah, but I don't think you can do that...at least I can't see how right now....that's the drawing I want to see. Because this would appear to be in the right direction because I think we all agree more elevatioon difference would speed things up. When I go to the CPR website and look at theirs...they appear to be at the same level to me.....just as with that diagram you suggested we look at.

if your skimmer box was not full of holes it would set the aquarium water level.

Hmmm....I'll study that other drawing again. I thought we had that one pumping uphill.

I'm beginning to think it might be time to trash all of this effort and just drill the thing. I had planned to do that eventually but I wanted to wait until I was sure I understood all the principles. Now I guess I can see that should be simple, this is the complicated one! You think I should just drill?

 

[the Wizard]

OK, maybe I see it. The key is to use an interior box as you suggested (no holes). And then the place the exterior box so that the spill wall is lower, but not so much lower that it is below the bottom of the interior box so that the siphon remains full of water.

So when the interior box is full then there is a true elevation difference in the water levels and the siphon should run faster. When flow into the main tank stops, and spill into the interior box stops, the water level in this box will be lowered by the siphon, and will slow, but at this point it doesn't matter, just so the siphon doesn't break.

Does that make any sense? I think this is what 68fj40 was trying to point out.

That drawing isn't very good at showing this....maybe I should post a better one if it works right.

 

[Anonymous]

i think you are there!

i was just pulling a photo of a C-siphon off a site and doctoring it to point out how it differs from yours.

the white lines are showing the elevation difference.