Water flow problems

[phoenixrising]

I have a 150 FOWLR that I recently plumbed into my system. I use two CS100 overflows. One of them drains into my filter and the return is connected to a Sea Swirl. The other overflow drains down into a 20 gallon sump under the tank. The return flows through a UV sterilizer and back up to the second Sea swirl. I hooked up this second overflow/sump because I wanted to increase my water flow in the tank and also wanted to include the UV in case of need.
The problem I am having is getting the second overflow to drain at the right speed into the sump beneath it. I'm using a Mag7 for the return pump (I have a GenX pump for the return to all my tanks from the main filter/sump). If the second overflow is too high by even a teeny bit, then not enough water drains into the sump beneath and the level in the main sump (connected to the filter) rises. If the overflow is too low by even a teeny bit, then too much water goes into the sump beneath and the level in the main sump drops.
Any practical way to level this out without sitting there watching it for hours tweaking it this way and that? I don't mind sitting and gawking at my tanks for hours at a time and in fact do so regularly, but I have to sleep sometime...and even WORK sometime and I would love to avoid a disaster when I'm not looking! Any suggestions?

 

[guppie]

I will take a stab at this IMO I think it is because the water travels through the uv before it gets to the tank. this will slow it down alot. One thing comes to mind is that you are pumping water too fast through the uv for the uv to do it's job. What size uv do you have, and you might want to check the flow rate.. You could add a gate valve to the output of the pump to adjust the flow.

 

[phoenixrising]

Thanks for the input! The UV is a 25 watt "Aqua". I didn't think of a gate valve. I have gate valves to control flow for the main return since it serves 3 tanks, but didn't think of one for this return. I suspect that this problem may continue to be a problem no matter what my return rate is though because of the 2 overflows going to different sumps. I'll have to double check what the flow rate should be for the UV. Good point that the water may be flowing through there too fast to be useful.

 

[broomer5]

PhoenixRising,
Your situation is not unique. It's just the way things work.
The problem is that since you have 1 display tank with two overflows draining to two individual NON-CONNECTED containers below ( filter and sump separated ) you will never be able to keep the levels in them identical.
The two overflows don't know the difference - they just overflow.
The two return pumps could care less - they just pump.
The two containers below have no interest in each other.
The only one that cares is YOU.
So in order to get all these pieces and parts talking the same language - is to connect the containers with some piping.
They must SHARE the common water between themselves.
Then and only then will the water levels in both be equal.
There's no way around it.
If not - no matter what you try, whether it's twiddling with ball valves or trying to adjust the overflow heights - the result will be the same. You'll be fighting the eventual different water levels down below.
Connecting the two underneath with bulkheads and piping is the fix. Water seeks it's own level - will do so 100% of the time.
( this goes for whether you have more than one display tank hooked into the system as well )

 

[phoenixrising]

Yep...sorta thought I'd have to do that. Only thing is that the sumps are roughly 8 feet apart and it would require draining the filter and both sumps. I was hoping that there would be an easier way. Bummer.

 

[broomer5]

One way that is easier - if your space and lay out permits - is to place your filter in a rubbermaid or plastic/acrylic container - up higher than your sump.
Allow water to drain to this container from one overflow. First you install bulkhead(s) in the top side of this container and run a slanted 8 foot run of PVC or vinyl tubing over to the sump.
Place both returns in the sump then - if you have room.
As water drains down the one overflow into this container - it fills up, but only to the level the bulkhead spillway is located. Water then runs over to sump.
Water in other overflow drains to sump as it always has.
Sump needs to be large enough to handle tank's drain down - siphon - upon loss of power.
Just an idea if you are interested.
It can be made to be fairly fool-proof, and dependable.

 

[broomer5]

bumped ^
I'll be back

 

[broomer5]

PhoenixRising
This may be an option for your dual sumps. It is a little risky though - and some extreme caution is in order.
I have two containers I use for RO/DI water and to mix saltwater.
This afternoon I was making some RO/DI water. I started out in the one container on the right. I allowed it to fill a few inches.
Then I took a length of vinyl tubing and started a siphon. Did the old "suck the air out and spit" trick.
I allowed the water in the right container to siphon over to the left container.
Eventually their levels became equal.
Water always seeks it's own level.
I then turned on the RO/DI unit again and let it run this afternoon, with the filled siphon hose still in place AND making sure both ends would not come out of the water.
Let it run like this a few hours.
As you can see - the level in one is the same as the level in the other.
Connecting two sumps with bulkhead fittings and piping would be the best ~ safest way to allow both sumps to "share" common water.
Sharing common water allows them to share common level.
But - I thought this was interesting and figured you might like to see it.
Here's 4 pics
One
Started siphoning from right to left.

 

[broomer5]

Two
Left starting to fill up

 

[broomer5]

Three
RO/DI running again - both levels equal

 

[broomer5]

Four
As I left it this evening - plenty of freshwater to get me through the week.
Both levels still equal.
You can see the vinyl hose draped over both containers.

 

[phoenixrising]

Broomer-
Thanks so much for the pics and the details!
Uhmmm........
I'm not the worlds greatest plumber (although I'm learning)...
You live very close (sort of)...
Any way you can be bribed to drop by and plumb this doggone thing for me some day?
Okay, okay! I'll give it a shot and see what happens. Sure hope I don't end up with a flood! Just got my basement finished again from the last flood (storm related, not from my fish). My insurance company (and my husband) would be ever so annoyed if it flooded again!

 

[broomer5]

Hey
I must have confused the whole thing.
Yes - doing a plumbing job with holes/bulkheads installed would be the best way.
This is something you could "TRY" if you didn't want to disprupt your current set up.
Cheap way to TEST THE IDEA and how it works on your set up, without having to drill holes and do plumbing yet.
If it works good - then move to plan B and do the permanent installation.
Got to Home Depot
Get a length of 1/2 PVC pipe
Get a 1/2" PVC elbow
Get a 1/2" PVC Tee
Get 3 1/2" PVC Caps
Build the "balancing piping" as below.
Red is Tee
Blue is elbow
Green are caps
Place the thing between your two sump-filter boxes.
Cap oth bottoms
Fill the tee until all the air is out and water comes out the top just a little ( make sure the thing is completely full of water )
Then cap the top opening in the tee very very tight.
No air can leak in the top of the thing won't work.
Then uncap the bottoms.
If it's full of water and there is no leaks - as one sump level rises - the water will move through this balancing line and the other sump will also rise. It will balance the different levels in each sump.
EVEN CHEAPER AND FASTER WAY TO TEST:
You could even try this with a length of vinyl hose - be even easier.
Take the hose and completely submerge it in a bucket of saltwater - so all the air is out. Might have to suck the air out.
Place your thumbs over each end of the open tubing. Don't let air in or water out.
Take this over to your first sump - and place one end underwater.
When it's underwater ( and secured ) release your thumb on it.
Run the other end over to the other sump.
Repeat - placing it's end underwater and secure it.
Then release your thumb.
Same thing will happen - both sumps will remain equal.
If one of your return pumps die - at least you'll have this balaning line in place to keep one sump from overflowing and the other one from running dry.

 

[phoenixrising]

A MIRACLE HAS OCCURED!!!!!!!!
I think I actually UNDERSTAND what you are talking about!! I will try it some time this week. Even with my "challenged" plumbing abilities, I think I can manage this one! Great pictures, THANKS!
Okay...just one question...how does the water stay level between the sumps when it has to rise up about a foot or so on either end and then travel a long distance. Don't laugh, I'm not a great plumber! Just seems like one sump will not get the idea to siphon the water back and forth. How does that work? How does the water in the hose know which way it needs to go? Is it due to the water pressure in each sump as the levels rise and fall?
One other quick question...is it better to have the return pump for this second sea swirl in the main sump (there is room) or in the 20 high that is under the tank?
Okay..one final question...I have tested my set up several times trying to simulate a power outage. The only problem I am having is still those Sea Swirls. I have 2 of them on the 150 and 1 on the 90. These things back siphon like crazy and I can't figure out how to drill a small hole in them to eliminate this problem. They are constructed in such a way that making a small hole in the actual unit is nearly impossible (since they are external wave making devices). Only the elbow itself is submerged and I can't find any suitable place on it to drill. The hose connects to the top of the unit, so I can't make a hole there either.
Any ideas?

 

[jarre]

Broomer you need to change your user name to RubberMaid!!!
Think this just gave me a good idea about my FUGE. I can use two Rubbermaid and get twice the room!
OT - Broomer what software do you use for your pics?

 

[reeflooker]

PhoneixRising:
When ever I face problems like the one you are having, I always ask myself....."reeflooker... what is the simplest possible solution to the problem"? Then I lay awake all night thinking about the simplest solution to the problem.
It seems to me that the simplest solution to your problem is a single sump, with the filter, uv, heater, skimmer,etc included. This is essentiually what Brommer5 is recommending,linking two to become one(sounds romantic!). So why not just use a single sump? A 30 gal sump, or bigger, should be sufficient for a 180gal display.
Why do you feel you need a uv? Some people swear by them, some people swear at them. Personally, I have never used one with my FOWLR, and I have had good results.
If you want to increase water flow, why not just add powerheads to your display or add a simple spraybar on the return?
Broomer5's designs and explainations are fantastic. We are lucky to have him as a moderator.
My recommendation.... keep it simple!
Good Luck - Reeflooker

 

[broomer5]

Phoenix
The whole "why does it happen" can be explained by the effects of atmospheric pressure.
Without getting into TOO much description - the Earth's atmosphere contains gasses and water vapor. Nitrogen mostly, but oxygen and most all the other gasses to some degree - and of course moisture in the form of water vapor ( clouds being the visible water vapor ).
We call it air - cause it's a lot easier than listing all the gasses.
The gasses don't float away - because they have mass. Mass is weight.
Anything with mass or weight is held to the Earth by gravity.
So here's this layer of gas and water vapor that surrounds the Earth - that has a definite weight.
We call it the atmosphere.
Since it has weight - it exerts pressure on the Earth.
We call that atmospheric pressure.
This pressure is about 14.7 pounds per square inch - and this pressure is pushing down on EVERYTHING on Earth. It presses down on us and on all surfaces.
We don't feel it because we have evolved here - or were created here - however you feel comfortable thinking about it.
We don't feel this 14.7 psi ( unless we go up a hill in a car or fly in an airplane and our ears pop )
So ............
You have a sump with water in it. Nothing else but water.
The atmospheric pressure is pressing down on the surface of this water. But the sump is a box - and there's no where for the water to go. It just sits there with pressure over it.
When we place a hose in a sump and suck the air out - we fill this hose with water. If the other end of the hose is "lower" than the end in the sump - water will flow out. This is a siphon.
If you raise the flowing end higher than the end in the sump - the flow stops.
It comes back to atmospheric pressure.
The 14.7 psi of pressure is pushing down on the water in the sump. The hose allows for the atmospheric pressure to PUSH the water up and over the edge of the sump. Even if it has to travel up a long way - the pressure is strong enough to do it. Then the water travels horizontally and drops down into the other sump.
1 psi of pressure equals about 27.71 inches of water.
In other words - if you took a 30 inch tall Pringles Potato Chip can - and filled it with water up to 27.71 inches - and stuck a pressure gauge at the bottom of the can - the gauge would read 1 psi.
The atmospheric pressure is 14.7 psi
Multiply 14.7 psi by 27.71 = 407.33 inches of water.
Take the 407.33 divided by 12 inches in a foot = 33.95 feet
33.95 feet of pressure just so happens to be called 1 atmosphere of pressure. Go figure.
So there's a lot of force ( pressure ) in the atmoshpere - and it can easily push some water up hill, over the edge of a sump - run it along a horizontal length - and it drops over the edge of the other sump.
How does the water know which way to go ?
Which ever sump is higher.
Each sump has the same 14.7 psi pushing down on it.
If one sump's water level is say 1 inch higher than the other, then it has the 14.7 PLUS the extra 1 inch of water pressure pressing down on the open end of the it's hose.
It has a little more pressure than the other sump's open end hose.
So the water HAS to move from higher elevation to lower elevation - it has more pressure.
If the other sump get's higher - then the flow reverses - but the reason why is same.
When both levels are equal ( balanced ) then no flow occurs.
This is why we can call this thing were talking about a "balancing" circuit or balancing pipe or balancing piping - whatever - it allows the water levels to stay equal.
Pretty cool - cheap and will work.
BIGGEST THING TO WATCH OUT FOR !!!!
If for whatever reason one of the ends of this pipe/hose thing is not completely submerged underwater at ALL TIMES - and if one or both ends are allowed to vent to air - then the siphon will be lost. The thing will no longer work. It is why I mentioned a little risk involved and some caution should be given to securing both ends underwater at ALL TIMES.
Naturally - if you drilled holes in the bottom of each sump - installed bulkheads and plumbed the two together with a length of pvc pipe - the risk is eliminated completely. If these two holes are down at the bottom of the sumps - then the water will move from one to the other as any water levels change - and we're not really doing a siphon anymore. We're just letting atmospheric pressure do it's thing. Same concept - but we're not lifting the water over to the other sump - we're just letting the differential water head pressure push it on over horizontally.

 

[broomer5]

Jarre
I just use Windows Paint as a drawing tool.

 

[phoenixrising]

I stand in awe! I get the picture now. I knew there must be a reason, but didn't know what it was! Thanks for an interesting discourse on the subject. I printed it out...as I have done with several of your other posts and it is going into my "fish notebook" where I keep a log of just about everything that happens in all of my tanks. Thanks for your input, as always it is appreciated! I'll let you know how it turns out!