Tunze 1074 Overflow Box

[mosuhu]

Hi Roger,

I have purchased one of these just this week. I was under the impression that the overflow box could handle 1200lph, but upon opening the box the included leaflet stated that it does 1000lph and then in the instruction booket it says 900lph.

Could you confirm which one is the correct maximum operating lph please.

Thanks.

Mo

 

[rvitko]

It can handle 1200lh, I suspect the 900 is a misprint and 1000l/h was the flow rate of 1074, the older model could handle less flow.

 

[mosuhu]

Thanks for confirming that Roger.

Out of curiousity, can the 1074 be used without the bottom inlet pipe? In other words to have the flow of water only from the wier?

 

[rvitko]

It would be possible with a much lower flow rate, but their is no reason to. The bottom inlet cuts out at the same level drop as the weir, so it is not a flood risk. Also, the surface suction is quite strong at the full rated flow rate with both running.

 

[mosuhu]

Hi Roger,

Could you tell me, if I added a second 'U' tube to the overflow box, what would this increase the LPH/GPH to or by?

Also, I have installed the overflow box, and my only option was to have the plumbing going straight down and then into the sump through some ball valves. The overflow box is quite nosiy, would you know any way I could quiten it down?

Thanks.

 

[rvitko]

A larger diameter pipe or better a corrugated tube like our 1075/2 would result in much less noise, the key is room for air to escape and a slower descent of the water.

1200l/h is possible with one U-tube, 1500l/h is possible with 2.

 

[mosuhu]

I am using flexi 40mm pipe very similar to the 1075/2. what if i restricted the water flow by closing the ball valve a bit? this would raise the water level in the pipe so there wouldnt be much of a drop...i think, dont know if this would work though.

 

[rvitko]

It would work, but I would avoid this if possible. The added restriction could clog. Is the end that opens into the sump submerged? If so, raising it so it just meets the water line would allow the air to escape with less noise.

 

[mosuhu]

Hi Roger, I bought an additional overflow tube and was curious, why do you supply a bushing with the tube? And how come the flow is only increased by 300lph by using a second pipe?

 

[rvitko]

The bushing is supplied in case it must be extended by an extension tube in a custom application. 1500lph is the limit of the overall box, it actually can do a little more but gets very noisy.

 

[mosuhu]

Thanks for the info Roger.

I have installed the second overflow tube, situated in the centre of the box, but it keeps collecting air. Any reason why this keeps happening and what can I do to prevent it.

Thanks.

 

[rvitko]

This would generally indicate the flow rate is not high enough or the siphon priming tube is missing the cap or taking in air.

 

[mosuhu]

In other words I need to make sure the return pump is capable of pumping upto the 1500lph rated for the overflow box with two tubes?? I will up the return flow and report back. The cap is present and its not taking in air, as I looked at what was happening and bubbles were being taken in from the bottom and just getting trapped at the top.

 

[rvitko]

This would mean the flow is too low to carry the bubbles through, the water is too slow moving and the bubbles accumulate in the u-tube rather than being swept through as they would at a higher flow rate.

 

[mosuhu]

Hi Roger,

I have noticed that the water level in the main tank has slighty gone over the normal line. What may be the cause for why this has happened, as I have tried to play with things but it doesnt change. I have not changed anything before this though.

 

[rvitko]

My best guess would be some obstruction of the drain line, if you used a valve, it may be collecting debris and clogging a little. Open and reclose the valve and this should flush it out.

 

[mosuhu]

I've checked the valves, both are in full open position but the water level remains a little higher in the tank. Could a possible reason be that the return pump is pumping a little more water than the overflow tubes can handle and thus increasing the diaplay tanks water line?

 

[rvitko]

This could be as well.