Herbie overflow tuning
 

So my new tank came with herbie overflow and I am having an extremely hard time to tune it to a constant level. No matter what, water level always goes down or goes up over hours. This is going to be a big pain with ATO.

So herbie overflow experts, please help :)

Are you using a ball or gate valve?
The key is making tiny adjustments and waiting 30min

Gate valve for the adjustment. So I adjust the valve and wait for 30mins and adjust accordingly? Do I have to do it everytime I turn on/off the return? And how often do I have to adjust it?

once you find the sweet spot it should be good. I find I need to open it fully once a month and flush it out.

Great; that's a relief :P Thanks for the info :)

I find when your sock filter starts to get dirty it ups the level in the overflow, change the sock for a clean one and it's all good. Agree with the sweet spot comment. Also make your adjustments small and like was mentioned wait 30 mins. to see where you end up.

Could you take a pic of it? It shouldn't be that hard to adjust. I'm wondering there is something odd about the way it is set up.

Do you have one or two overflows? If two, are they plumbed together with a single outlet to the sump?

http://i1304.photobucket.com/albums/...ps853b060c.jpg


Its just a single overflow.

Yah people do say filter socks sometimes cause more problem than good and so I decided to not use any socks. Will put some sponges between the baffles.

It's probably one of three things

1. Operator - improper adjustment, it can take a bit to find that sweet spot, you can sometimes adjust it close to the point walk away only to hear it slurping air a couple minutes later. Then you over compensate in the other direction, always missing the actual point.
   
2. Air draw - flow rate is too high for primary pipe in overflow height. The higher the flow rate and the smaller the pipe diameter the higher the intake velocity. The higher the intake velocity the more space you need from the top of primary pipe to operating water level in the overflow. If the space is inadequate you'll gnerate the occasion vortex with brings air into the line which messes up the flow rate.
   
3. Inconsistent return flow rate - a few things can cause this but your return pump has to pump a consistent flow rate. Obstructions at the pump intake, air bubbles, poor quality pump are all examples.

http://i1304.photobucket.com/albums/...ps9eaa8ba4.jpg

Relating to 3 in my previous post, what's the green stuff with the pump?

Also the return chamber is pretty small, you'll have to do the final tuning once everything is at equilibrium (overflow water level and sump water level at permanent state),

1. Operator: Yah that might be the issue; I tuned it yesterday evening and it was remaining at the same level for about an hour. Afterwards, I left my house and didn't check back yet to see the level. Will be checking it after an hour or so when I go back home.

2. The overflow is silent and no bubbles can be seen from the output. But slowly, the level goes down (draining more than return I presume) and then the gurgling starts till I readjust it.

3. Its the speedwave 790 running at 3th speed (or 4th; can't really remember :redface:).

Oh those are foams. I used those to temporarily raise the pump since, because of my mistake, bought inadequate amount of clear pipe. Will get a longer pipe, hopefully today. Also removed the foams the last time I have been to my house.

The lower the gate valve is the easier it will be to adjust, mine sits 1" above the water level in the sump, without an ATo you'll find yourself adjusting it as the sump level goes down as it changes the flow, also barometric pressure will affect it, all minor things but something to consider, on my 8' tank with ato I never adjust it, my 75 with baffles I'm constantly adjusting it

I usually go with a bare tank and ATo for a sump if I'm running a herbie.

Your first chamber would freak me the F out everyday, I wouldn't be able to not check the tank 1000 times a day. Water level being right to the black edging.

When I tuned my Herbie in I had no problems what so ever, I also used my emergency drain to drain into my refugium, maybe try to turn your overflow box up to the top of your Emergency drain and let it take the extra water back into your sump. It seems your 1.5 PVC can't handle the amount of GPH your return pump puts out, by routing down your emergency drain just a little it would make up for this downfall.

Don't use emergency drain for anything else other than emergency situation only. The emergency drain should remain dry under normal operation. Doing it otherwise will defeat the purposes of the herbie system, i.e. fail-safe and silence.

I disagree completely, yes the drain is there for an emergency but honestly a trickle through the "emergency" drain isn't going to be the deal breaker... If you really want to do the math go for it.

Just because it has the word "emergency" people get their panties in a bunch. Especially for such a low flow and small tank. I would maybe think differently if I was setting up a 200+G as the flow is way higher. When I was researching the math and water movement in a 1'' bulk head herbie/durso style I believe it was that one single drain would drain approx 600/800gph depending on gravity and how long your herbie drain is in your overflow box. So if your are running a 1.5'' bulk head then that number would increase.

So if you're telling me you would be worried about 20-30GPH when your Single drain in a 1.5inch bulkhead which is common is going to affect your 800-1,200GPH your currently running through your single drain that is mind boggling.

i too found that my water level would very about a 1/2 inch .

This is why i increased the height untill just a trickle was going down the emergency drain . no is stays exactly there for weeks now .

the emergency drain is still perfect .. If you think about it . You are restricting your main drain .. mine is restricted about 1/2. So if the emergency drain is wide open and only taking a trickle down it then it can easily handle the flow of your main drain .

Eaither way you need to do a test by completly blocking your main drain .. shut the valve .. and see how the e drain handles ..
I orginally had the e drain set to high , and water was getting to close the the edge of the tank before properly flowing down the e drain..

good luck

so your saying a 1" pipe cant handle 790g at full siphon?

I don't remember the exact math on the GPH on a 1'' bulkhead. Its very hard to do the math to a accurate measure. It depends on so many things, how much weight is above the standpipe, how far its travelling, how long its travelling, then to toss in your return pump and gph.

I just used rough numbers for reference.

Here you go for number reference.

http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml


Looks like the numbers were slightly higher.

Not an overly accurate chart to use for our applications, especially seeing how it's based on 100 feet of pipe.

For example using a 1" pipe with a pressure drop of 4 feet will give an initial entrance velocity of about 16 f/s meaning before you consider pipe friction you'll get about 2300GPH. You can calculate your friction losses by yourself but you're not going to loose much more more than 25%.

Only thing I could find. Regardless I wouldn't be worried with 20-50gph running through my "emergency" drain.

You can use this calculator. It will tell you how much flow a pipe can take given diameter and head hight.

http://www.beananimal.com/articles/h...-aquarist.aspx

make sure you click the "Submerged Discharge" radio button in the calculator. That's a for Herbie or BA

I don't see anything odd about the plumbing setup. I think you're either trying to get it too perfect (ie trying to have no water going down emergency drain) or you're over compensating each direction. Fwiw, I always keep a small trickle going through my emergency drain as well. If the main line is starting to get clogged up and there is significant water going down the emergency line it makes lots of noise (good alert). Getting it "perfect" is terribly frustrating. My ATO pushes a bit of extra water down the emergency drain while it is running, but this is definitely not a concern.

Thanks everyone :)

I guess I will have a small trickle going down the drain since I don't want to keep on adjusting the water level every now and then. I will have to extend the emergency drain to submerge inside the water now since I left it over the water level to make a warning sound :razz: