Flow Issue

O

OctoPunk

Hey guys,

I'm setting up a 55 gallon with a 20 gallon sump/fuge right now and I'm having a bit of trouble. this is my first big tank. the last one being a 20 gallon with a HOB filter so never had to do any kind of plumbing before. I've been doing alright so far I think, only a few mistakes to speak of so far....here's a little info on the set up (I have done everything myself so there may be some mistakes mixed in here so if you see any let me know so I can rectify.):

-55 Gallon Tank 48x13x20 and 20 gallon Long aquarium for the sump
-Drilled two returns, one on each side of the back of the tank. (1" diameter PVC)
-Drilled two drains , both in the middle about 5 inches from the top. (1" diameters PVC)
-Built and installed an internal overflow insert made out of black acrylic using about 15 teeth to create a flow of about 1400 GPH.
-Both drains have a t-fitting with a air hole drilled at the top on the outside of tank right off the bulkhead. (both have ball valves)
-Drains empty directly below it about 3 feet in height (eyeball estimate)
-2x Hydor L40's (740GPH) one for each return line.
-Return-line head height is about 3 ft. and the lift is about 3.25 ft on one and 1 ft on the other. (Both returns have ball valves and ball-check valves)
-Sump has three sections, refugium, skimmer and return. (with a bubble trap between the skimmer and return section)
-The first chamber is the fuge (where the drain empties) followed by the skimmer and then return. Separated by baffles of thin glass cut from Home Depot. (bad idea for the baffles BTW - they broke so many times.)
-Protein Skimmer is a ASM G1X.
-Fuge has/will have different Macros live rock and deep sand bed. (6")
-The fuge is the largest section, followed my the skimmer with the smallest section being the return. (possibly problematic)
-Main D has 2 inch live sand and 50 pounds of live rock and 20 pounds of dry rock.

That's what got so far, I still have quite a few thing I'm planning on doing, including this weekend I will be modifying the drain for a reverse durso, because the drain is quite loud right now and I'm getting bubbles in the sump right where the drain empties.

I will also be modifying the return to include a t-fitting splitting off and emptying back into the skimmer chamber or fuge (haven't decided which yet, and advice here would be nice)
<u>
Now on to my problem:</u>
My return line section is draining of water to the point where the pumps are sitting out of water, it seems like the water is not coming over the baffles fast enough (I do not have teeth on any of the baffles). I can adjust the ball valve on the return to make it work but I know that is going to ruin the pump eventually so I need a more practical solution. The return section is a bit to small and it is by biggest regret on this build. It is only about 6" wide on the inside, with two L40's in there, it is very tight. Even after turning off one pump, I still seem to be having this problem. So I'm curious, is this something where i will have to change the size of the chamber or do you think I could just increase the flow by placing a pump in my refugium to push the water toward the baffles?
I don't understand because each of my drains should be producing about 600 GPH for a total of 1200GPH which should be more than enough for these pumps right? I have heard a little bit about the pressure in the return line increasing the the rate of flow for example I read somewhere that a pump with a 1200GPH rating and 100psi of pressure in the piping would produce a total modified GPH of 2200...or something like that. If that's true then that would explain why this is happening. I had just never heard of this before so not sure what to do. Any advice would be helpful. I'm going to take pictures tonight when I get home.


P.S. - How do I find out what the pressure in my return lines are?
 
@OctoPunk wrote:
Now on to my problem:[/u][/b] My return line section is draining of water to the point where the pumps are sitting out of water said:
When you turn off your pump, Does your Sump fill all the way up? or is there room for more water?
Click to expand...
 
You don't need or really want to push that much flow through the sump. Typically you wound want about 8x the water volume or 450gph max.

How big are the drain holes and how far under the water line is the pipe? This info will give est of drain rate (but again, you don't want 1200 or 1400gph!)
 
When you turn off your pump, Does your Sump fill all the way up? or is there room for more water?[/quote]

fills all the way up.
 
@Charlie wrote:
You don't need or really want to push that much flow through the sump. Typically you wound want about 8x the water volume or 450gph max. How big are the drain holes and how far under the water line is the pipe? This info will give est of drain rate (but again said:
the drains holes are 1" each I mentioned that in my original post. and the pipes are about 5 inches underneath the water line. The overflow never actually fills with water though. it is constantly being drained down the pipes,creating noise....... [smilie=sadsmile.gif]
Click to expand...
 
After some further reading I have discovered that the rating of 600 gph on the drain is only good for drains located at the bottom of the tank because of pressure. The way I have it set up, there is no pressure. The water is flowing down the drains faster than than the overflow teeth allow, because my drains are only located 5" below the water line of the tank on the back glass. Which brings another level of confusion to the mix, because the overflow box being utilized is rated at 1400GPH and so if the drains are only pushing say 320 GPH each for a total of 640 GPH than why the hell is the overflow box not filling with water!! This stuff is so confusing......I'm overwhelmed.
 
1- having two large diameter return pipes is a problem for your small return section. Your return section MUST hold more water volume than the pipes volume + volume in overflow. You will need to use smaller plumbing or enlarge your return section.
2- personally, I would fully cap one drain line and let it be a full, completely silent siphon, using the second pipe to drain whatever the first one can't handle on it's own. Then you can move the valve on the full siphon drain to a "sweet spot" that stabilizes your water level in the overflow box. That's called a "herbie" overflow (research it, it works great). That change will keep your box from emptying completely and eliminate that noise.
3- as suggested by others, you really need less flow through your sump. Using only one of those return pumps would probably be about right. Also eliminating the damage from having the return lines "valved down" to the gph you are looking for. You don't usually want your main tank flow to be all return flow. Use powerheads in the display tank to reach your needs.

Don't get stressed and take your time! Many people here to help!
 
To clarify, by "cap off one drain" I mean the air hole in the durso. Even just make the T fitting a 90 if it's not already glued permanently.
 
Could you post a pic of your overflows as well as the sump? Preferably as the return pumps are running. It does seem like the return area will be too small with the depth of the holes you have in the tank, but it depends on the overflow design.

How big is the fuge area in the sump? There is likely no value at all in the DSB. There needs to be quite a bit of surface area to have much value. The entire sump should only have a water depth of 7-8", since you will have 8-10 gallons draining to the sump when the return pump is off.

Most likely the issue is that the baffles are too high and the sump needs more water in normal operation, causing a flood with the return pump off.

1) Get rid of the thin glass baffles in the sump assuming it's 1/8" glass from HD. You can use 1/4" acrylic, just silicon it in place. The 1/8" glass will just break at some point in the future. You might have double stacked the glass, but 1/4" acrylic is an option if not. I've had good luck with acrylic siliconed in place on a sump, it might bow slightly, but works fine.

2) Go down to just one return pump. You only need the first 500 gph. Save the other for a backup. Use powerheads for in tank water current. At 1200-1500 gph on the return, your fuge won't add much benefit since it does not have much contact with the gushing water flowing by.

3) You might research bean animal for the drains. They require 3 drains, but it is quiet and would possibly work with another drilled hole.

4) You might post in open forum for someone near you to come by and take a look. It's much easier to understand with seeing it in person. Pictures do help at least.

Good luck!
 
The problem is just too much water filling up your Display tank and pipes, also due to too small of a return section in your sump.

First thought is how high does the water in your display tank rise when you turn the power on? Are your check valves working (they should eliminate the water draining from your return pipes but they seldom work and rarely for very long. you can also tell if there a bubbles when you turn the pump back on working checkvalve = no bubbles.

If the display tank water is increasing more than 1/4" you either have a weir problem (removing teeth or expanding the size will remove this issue)

Or you have a drain problem. (sounds like this is not the issue but going this route will eliminate the noise)
Going to a modified herbie will solve this issue. remove both ball valves throw one out, replace the other with a gate valve (you can try it with a ball but success will be limited) Remove the T fitting on the gate line and add a 90 in place so zero air will enter the line. when you start the pump again slowly close the gate valve until the air stops getting sucked in. You will need the input for this line about 2-3 inches below the other input for the open channel or durso line.
Those are my best guesses without a picture. Post one and we can add some more comments.

IMO the weir teeth are likely the largest issue.
 
Thanks to all for the input! really appreciate it. Got me thinking on the water physics surrounding aquarium design. Helps me understand how they work better.
It turns out however that they problem I was having was stupid and simple......It turns out I did not have enough water in my system!!! man I'm dense, haha. I was afraid to put in more water because i didn't want a flood in case the power went out. it turns out I could have added more without it flooding. I added about another 3/4 gallon of water and the system runs great! the only issue is of course the noise. But i figure that the noise is partly due to how much water is flowing through the system. with both pumps running it is definitely a "GPH Beast"! It is definitely more than I need, haha and I will probably not use it because Like ya'll said it will hinder the biological filtration in fuge. Which is fine by me, i'm happy with the GPH with just the one pump for sure.
As far as the noise goes, at just one pump the noise is completely gone! Apparently the noise can be attributed to the system being brand new. The tank needed a few days to develop a slim coating over everything which makes flow smoother without as much friction. I also increased the length of the drains to empty under water in the sump, this helped out with the noise tremendously. Tonight I will be adding a reverse durso to help with my last issue which is bubbles and bubble noise (slight) in the sump where the drains empty.
I am also going to added a valve and t-fit to both returns to regulate flow whenever/if ever I need it. Both will empty back into fuge or skimmer section.
As far as the herbie mod goes, I'm not going to drill another hole. That would pretty much be like starting over at this point. i would have to drain and take everything apart and build an larger overflow and the put the thing back together, as well as plumbing the new drain. Way way way to much, especially considering how well its working now. However I do like the idea of having some of its functionality so I could do what one you guys said here in this thread. That is to turn one of the drains into a siphon and leave one a durso to pick up any slack from the primary drain.
Also in regards to my returns leaking back into the sump. No they do not do that yet. The check valves are still doing their job. I haven't noticed the display tank water height rising so it must be quite the small variation.

Really appreciate all the info guys, and I'm definitely going to need more help.....As a matter of fact I do have another issue now, concerning my light fixture. I have a 48" Wavepoint T5 HO, That I got used a few months ago. I replaced all the bulbs (except for one ATI Blue Plus) and have only turned on the fixture for testing purposes as the tank was not set up yet.
Since the tank has been cycling I have had the light running on it. The other day I noticed a change in light output out of the corner of my eye while in the room where the tank is. I looked over at the tank and noticed that the colors looked a bit dim, but thought nothing of it. A few minutes later when I happened to be looking at the tank I noticed the light change. This time the light got brighter...and pinker ( I have a bulb that is purplish pink). It turns out that two of the bulbs are going out intermittently and then coming back on the same.
I opened the fixture up and an traced the socket wires of the effected sockets back to the same ballast. So I'm assuming this issue has to do with the Ballast. I mean it could be a wire but everything is tip top and new looking in this fixture so I'm leaning towards bad ballast. These Fixtures have a water tight seal, so everything inside the fixture looks brand new. No signs of heat damage or any damage at all to speak of was visible. A new Ballast is like $50! Ridiculous, I really don't want to buy one. I wonder if the ballast out of my 24" wavepoint will work? Doubt it but possible.
Anyway I wanted to know if you guys think this is probably the only answer. I also wanted to know if anyone knows How i can get a ballast for it locally. i hate ordering things online. I want the item when I pay for it, not a week later....ya know.

Thanks guys!
 
Most likely is the ballast. Unfortunately outside slowly replacing sockets, wires and bulbs, just no easy way to determine the issue. You could measure voltages at various points but the readings aren't much of an indicator of what is causing the issue.
 
If a t5 Fixture gets to hot would that possibly create a situation where the ballast overheats and shuts itself off to protect itseld then turns back on when it cools down?
The reason I ask is because when this occurred I did not have the fixture set on top of the aquarium by its legs or arms (whatever they are called). When I was experiencing the issue of the two bulbs turning off then back on intermittently, the fixture was laying on the top of the aquarium without the legs holding it above the glass top. In this situation the glass on the bottom of the fixture was in direct contact with the glass-top of my aquarium. This created a serious lack of air circulation under the glass of the fixture, essentially stifling the fixture with heat. This factor mixed with the fact that The WavePoint fixture in question is completely sealed (rubber gasket), I mean this suckers gotta be air-tight. May or may not have be responsible for the two bulbs turning off and then back on a few minutes later.
Another reason I'm leaning towards this hypothesis. Since placing this fixture back onto its arms/legs and then placing it back onto the Aquarium (properly) and running it for a good long while. I have not been able to reproduce the issue. So I'm thinking that the fixtures placement may have been the culprit here. Can someone possibly verify this?
 
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