Leak test was a complete success.

The return pump is so noisy. I need to get a mouse pad or a piece of foam under there. That is also 8" of water in there.

https://lh3.googleusercontent.com/-7...4/IMG_4284.JPG

This picture shows the water level when the pump is on. You can see that I decided not to drill any siphon break holes into the pipe as the end sits above the water level at all times.

https://lh5.googleusercontent.com/-L...4/IMG_4286.JPG

And when the water is off, this is where the water level is at.

https://lh5.googleusercontent.com/-q...0/IMG_4285.JPG

So I am having problems with the herbie setup. The emergency drain is currently 1.5" taller than the full siphon drain. The water is gurgling into the emergency drain.

https://lh5.googleusercontent.com/-r...4/IMG_4282.JPG

https://lh4.googleusercontent.com/-0...0/IMG_4283.JPG

Do I make the emergency drain taller by another 1 inches?

Also, I can hear the water splashing from the weir into the box. Do I need to raise the full siphon drain as well? sphelps help, I forgot what you said when you came over.

Tomorrow I am going to start washing the oolite sand and will let it run with the fresh water, to settle. It's brand new sand. Then I will drain the tank and do the transfer. My 90 is currently sumpless but is bare-bottom. :redface:

Does it make sense to transfer it all at once, or should I fill this tank with salt water and migrate it slowly? I was thinking that I could siphon all the clean water for the transfer. There shouldn't be any issues with parameters this way??

I ended up putting a piece of this filter material under my 1262 to silence it. I chose the green for it's cushion feel over the others available. It's a bit more than an inch thick and I use it under 4 different pumps with great results

If it were me, I'd lower the full siphon pipe. This will give you more flow due to more head pressure
My main drain is only about 4" tall and my emerg is a couple inches from the top

48x18x18 is closer to 67g

Hey there. Just like to start out by saying NICE TANK! Smart idea with the stand as well. It looks pro. To the Herbies. There's a happy spot you'll have to experiment to find. Every system is a bit different due to flow rates and weir heights. I found with mine that keeping the overflow water level higher it would make it quieter. Also I'm not sure if you're using fresh or saltwater in your test but things will change with saltwater and once the pipes start to 'slime up'. I ended up with some enkamat in the back of my overflow to help keep everything quieter as well. Are you using two drains as primary and one as an emergency? Once set up, you may have to have your primary drain 3-4 inches lower then your emergency just to get a decent head pressure above the drain. Once you cut your primary drain down lower the overflow should fill above the drain pipe at least an inch or two to keep the suction/gurgling sound away. Its all about throttling and matching the flow of your return pump. Herbies are great and I wouldn't go any other way. Just some set up involved.

Also if you want to chat a bit more in depth about it or you have any further questions shoot me a pm and I'd be glad to call you or vice versa

First off don't lower the full siphon pipe yet (primary, one with gate valve). This won't increase head pressure or flow, this is set by the gate valve and nothing else. Lowering the height will only drain more water to your sump and that's a pretty big overflow you got there. You may need to lower it if it's creating a vortex and sucking in air but I don't think that's an issue.

Seems to me the issue is your back up or emergency drain is too low. Try this procedure.

1. Stick a coupling on there or swap out the pipe with a taller one. Start with something too tall that extends an inch or so above the top of the tank, you can cut it to the right size after the next step.
   
2. Tighten the gate valve a little to raise the water level in the overflow, it's too low if the weir is dropping down too much causing waterfall noise. Water level in the overflow can be around 1/2" to 1/4" below tank water level, but set it as low as possible provided the noise is gone. The overflow should be completely silent now, if not check if the primary is creating a vortex and sucking in air, if it is the primary pipe needs to be shortened.
   
3. Now with the overflow water level set, mark the back up drain pipe 1/2" above the overflow water level and cut it there. I recall you have three drain pipes, so consider running two back ups at this height, it'll help for next step.
   
4. Now test the back up, with pump operating at desired or max output shut the gate valve completely but be ready to open it if needed. If the back up drain(s) can handle the flow without the tank overflowing you're good. If not you have to shorten them until they can, 1/4" at a time but note if you have to cut it more than once you'll need to lower your overflow water level in step 2.

I've had my emergency that close to my primary. They key is making really fine adjustments to the gate valve so that the trickle going down the emergency is small enough that it is silent... like a thin coating of water on the walls of the pipe going down.

Actually lowering or removing the primary drain standpipe will make life a lot easier in this configuration and it has everything to do with "head". Everybody remembers their first go at trying to adjust a herbie style overflow, even if you did shell out the bucks for a gate valve it can be a complete PITA to try and maintain with the primary standpipe that high.

However if you were to remove the primary drain standpipe and close the valve controlling that drain until the water level in the overflow stays within and inch or so of the top it so it's quiet as well it becomes much easier to do minute adjustments. The reason for this is the pressure built up in the box remains constant when it is at at given level, with a high drain pipe you get much less drain pressure and it fluctuates somewhat making it difficult to adjust. The force of the water is "static head", not to be confused the the "head pressure" we try and work out when sizing a return pump.

Some things to consider in this configuration; When the pump shuts down you will drain the entire overflow box, make sure you have room to catch the water. Also you are at a slightly increased risk of clogging the drain, make sure you open it up once in a while to flush built up gunk. You should be doing that in either configuration though.

Greg - I edit that part out. I realized I wasn't using an aquarium calculator. duh!

Skimmin - Thanks for the kind comments. I was able to leave the return pump fully open.

Steve - Your method worked very well. It sure is time consuming and cutting a 1/4" of PVC off on the mitre off is scarry. The rebound and kick back sure is dangerous.

Brett - I have my emergency drain sitting high in the sump so the thin drain doesn't work. I did this on purpose so that I could whether something was wrong with the primary.
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Thank you everyone. I ended up cutting the primary 1" and the emergency is now sitting 1/4" under the weir itself. No crashing noises or vortex happening. The emergency also works flawlessly.

I stuck a piece of 1" gym memory foam under the return pump which helped some what dampen the noise, but you can still hear a hum/vibration. I'm thinking maybe it's the vinyl tubing from the pump to the hard pvc? Or maybe I am hearing the echoing inside the stand itself?

There are only two drains on this herbie.

https://lh3.googleusercontent.com/-v...0/IMG_4290.JPG

https://lh3.googleusercontent.com/-y...0/IMG_4288.JPG

https://lh3.googleusercontent.com/-8...0/IMG_4287.JPG

Thanks for the tip. I didn't glue the stand pipes in for maintenance purposes. Also when I open the gate valve completely, it does a nice job of flushing the sump so that should be a regular task.

I chose not to use the ball valves to limit the return pump. Kinda silly since I them on there already huh? I think I'll stick with the stand pipe.