Hi

I think a solution similar to this



you can see the "tower" on the left and on the right.

the cap has a thread and is screwed so you can open and inspect the inside of the tube; moreover on the cap there is a no return valve.

I think this could be a good idea.

Just a question for you: I saw that all american diy overflow pipe are made with white pvc; here in Italy I found only gray pvc.
what kind of pvc do you use?

bye

Looks like that would work.

The removing the cap will allow the functions I used with the Purple nillple labeled "primer" on the original drawing.

Some have used grey pvc here so that should work as well.

Depending on space I would "flatten" it out so the drain is flat against the aquarium glass. That way there will be less twisting on the tank top and back glass.

But I think you have a workable system.


my .02

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fw leiden since 1979, fo salt since 1979, mixed reef 55g 2002-2009. Strong emphasis on the tank taking care of itself. Balanced with plant life, no water changes, tap water, no filters in FW. Only dosing calcium, alk, mag in marine reef tanks. http://www.aquariumforum.com/f15/my-...ods-26410.html
recent tanks (till 2009) 7 years- 10g FW leiden 7 yrs, 55g mixed reef 7, 2 yrs, 20g FW leiden, 10 g fw leiden , 29g mixed reef, current tank 55g leiden

This system that is depicted in the animation works awesome BUT...I have a flow rate issue. Tables show that my Eheim 1250 is flowing about 165gph at 4' of head and it is way more water then the down pipe can handle.
I made my down pipe with 1 1/2" I.D. PVC.

I figure there are 3 ways to solve this issue:
1) Get a smaller pump with less flow rate
2) Make a second down pipe system or make another one with a larger I.D.
3) put a dimmer switch for a light fixture in-line with the pump power to slow down the impeller.

I am thinking option 3 will be the cheapest and will allow me to 'dial-in' the flow rate. There is no need for me to cycle my 55 gallon tank 3 times in an hour.
Any thoughts?

1 1/2 pvc should have no problem handling that flow rate.

I say build it and test it out.

my .02

__________________
fw leiden since 1979, fo salt since 1979, mixed reef 55g 2002-2009. Strong emphasis on the tank taking care of itself. Balanced with plant life, no water changes, tap water, no filters in FW. Only dosing calcium, alk, mag in marine reef tanks. http://www.aquariumforum.com/f15/my-...ods-26410.html
recent tanks (till 2009) 7 years- 10g FW leiden 7 yrs, 55g mixed reef 7, 2 yrs, 20g FW leiden, 10 g fw leiden , 29g mixed reef, current tank 55g leiden

On second thought...Changing the speed of the pump would drastically affect its efficiency. Maybe diverting some of the flow is the answer?

as I remember HOB overflow boxes with 1" diameter U tubes are rated over 600 gallons/hour.

So as I said just build it. It should work just fine.

my .02

__________________
fw leiden since 1979, fo salt since 1979, mixed reef 55g 2002-2009. Strong emphasis on the tank taking care of itself. Balanced with plant life, no water changes, tap water, no filters in FW. Only dosing calcium, alk, mag in marine reef tanks. http://www.aquariumforum.com/f15/my-...ods-26410.html
recent tanks (till 2009) 7 years- 10g FW leiden 7 yrs, 55g mixed reef 7, 2 yrs, 20g FW leiden, 10 g fw leiden , 29g mixed reef, current tank 55g leiden

would be a disaster I wouldn't want to come home to.

I Looked into non-drilled overflows using a configuration of pipes, and all i came back with was to get ma dam tank drilled!

Its seems a hell of a lot easier?..no?

But to my defense...all i did was google and youtube for a few mins until i got the "cave man look" like huh???

Which method do ya'll think is better or prefer - drilled or over the tank siphoning?

Is it worth the trouble really?

Way late on this but drilling existing tanks especially the bottom glass is extremely dangerous. Because it is probably tempered and will shatter.

I have hear some tank side glass is not tempered and can be drilled.

Either way I would recommend the hang on syphon designs here.

If your tank is already drilled it might be better looking to use the existing holes. Plus some like eliminating the possibility of breaking siphon.

On the other hand using power head(s) to suck out air in the HOB part prevents the siphon loss. Plus the hob overflow can be easily taken off the tank for inspection and cleaning.

my .02

__________________
fw leiden since 1979, fo salt since 1979, mixed reef 55g 2002-2009. Strong emphasis on the tank taking care of itself. Balanced with plant life, no water changes, tap water, no filters in FW. Only dosing calcium, alk, mag in marine reef tanks. http://www.aquariumforum.com/f15/my-...ods-26410.html
recent tanks (till 2009) 7 years- 10g FW leiden 7 yrs, 55g mixed reef 7, 2 yrs, 20g FW leiden, 10 g fw leiden , 29g mixed reef, current tank 55g leiden