Siphon restart issues with overflow

[meicalnissyen]

Greets, and apologies for a question that has probably been dealt with in the past..

I have added return and overflow to my stack of tanks, I plan to drywall around it once its stable and reliable. viewing is on both long sides with full access to plumbing only from one end (hope I am not creating a headache)

I've attached 3 pics
I made intank overflow boxes with 2 bulkheads, and a pair of elbows, one turned up for emergency, one turned down for a quiet siphon. this one has a gate valve.
the top and middle are plumbed this way, the bottom tank serves as 2/3 display and 1/3 sump, and simply overflows across a weir

Problem 1
from a power down static turn on, the siphon overflow has trouble burping trapped air, and establishing a true full siphon. I've either created an issue with the way Ive submerged the return, or, i over simplified the siphon setup in the overflow box.

Problem 2

Even with the gate valves, I am having trouble keeping the flows balanced enough so that it consistenly sits with a trickle , or no water from the emergency overflow.
this may be variations in the return pump out put, or perhaps problem 1 is contributing, or the way I plumbed the emergencies, I have them going straight to the sump, and they make a bit of noise that way, which I consider good, but, should the top tank begin using the emergency a bit, it diminishes the return to the middle, a bit, dropping the level in the middles overflow box.

This is a fairly low flow system, I'm proly only getting 250-300 gph with the 7 ft of head and pipe fitting restrictions, valve slightly closed etc
both overflows are 1" pipe.

I appreciate your comments and input.

 

[lmm1967]

ummm - are you sure you want to use a metal gate valve?

My personal opinion - if you are going to make the plumbing semi difficult to access in the future I would go with a bean animal (3 drains - not just 2).

https://www.youtube.com/watch?v=pglqSH-4cTo

Example of my DIY overflow setup on a 60 gallon cube - has been 100% no touch so far.

 

[meicalnissyen]

ummm - are you sure you want to use a metal gate valve?

My personal opinion - if you are going to make the plumbing semi difficult to access in the future I would go with a bean animal (3 drains - not just 2).

https://www.youtube.com/watch?v=pglqSH-4cTo

Example of my DIY overflow setup on a 60 gallon cube - has been 100% no touch so far.

# holes may well have been easier to tune, but 10 1" pipes in a 10" space makes for tough access.

what would you do to make the siphon overflow more forgiving? IE flow a bit more as overflow box level rises.


whats wrong with bronze valves?

 

[mcgyvr]

ummm - are you sure you want to use a metal gate valve?

Looks like a freshwater tank..

 

[lmm1967]

A 1" full siphon will drain a whole bunch of water. Perhaps a cap with an air tube choke will help your situation

I keep all metal out of my tank - even when I had freshwater / cichlids.


Sent from my iPhone using Tapatalk

 

[meicalnissyen]

Looks like a freshwater tank..

Damn right

13" oscar
10" red devil

I'm here because reef peeps are way smarter with plumbing

and this is a plumbing issue

I was a reefer 20 years ago, its like a boat

 

[Lsufan]

The first thing to check when the syphon is having trouble purging air is to make sure the exit of the syphon is no more than 1/2" to 1" submerged. Any more then that & it will have trouble purging the air.

 

[LXXero]

lol i posted here for help with my 120g mbuna tank too, dont feel too guilty.

i'm actually building a 60 cube reef now, so i can pretend to be part of the club for real, haha.

Anyway, the first thing everyone will tell you to do is to make sure the full siphon drain pipe isn't too far under the water level in the sump. that will cause enough back pressure that it won't ever be able to push the bubble out.

me personally, i'm not really comfortable with being a few inchs too high of water from my siphon starting, regardless of how far down or not far down it is.

My solution? Drill a hole in the 90. Do it right where the 90 turns horizontal. In fact, in your third photo, there's a little dimple on the plastic in nearly just the right spot, maybe a tad higher than that. Also, you usually want it to be lower than the water level sits normally in the overflow during operation, but higher than it would sit when the pump is turned off. Now, backpressure doesn't matter. You're popping the bubble, the siphon will start each time.


what ppl wont tell you is that even the pvc gate valves often have metal exposed, even my freakin $60 spears one from BRS has part of it exposed. but, i'd still suggest you replace that bronze one, there could be heavy metals leaching out of that stuff over time, although there are varying grades of bronze....i just don't trust it on an aquarium which can be somewhat corrosive, even a freshwater tank could rust a piece of metal out pretty damn quick, yes bronze will last longer than something easily rusted, but it's still not the best thing to use. At least the $60 spears one, i'm pretty sure whatever they used for the metal is probably the highest grade stainless or whatnot, and it's also a rebuildable valve, so you can actually fix it if it breaks. Just spend the $$$ and get the spears pvc gate valve. The 1" one is like half the price, I know cause I just bought one for my 60 cube build, lol....its like $35ish. i used 1.5" on my 120g and it was definitely $$$