Non Uniform Flow from Extended Spraybar

[John S]

I have an Eheim 2078 and wanted to increase the spraybar length to match the length of the tank. I got an Eheim extension bar (400mm) to add to the standard one. I, wrongly, thought the 2078 would have enough power to drive it, but the far end flow is far greater than the input end.

Without going down the route of making a new spraybar is it possible to modify what I have by either masking off holes (reduce number of holes) or use a 'sleeve' over the current spray bar to effectively adjust the hole size size (keeping same number of holes)? The latter would obviously mean the holes are a D shape as opposed to an O shape.

Cheers,
John

 

[Alastair]

You could possibly blOck every other hole up that would help. I would have thought the far end would have the least flow :0/

 

[hinch]

naah strongest flow will always be at the sealed end assuming water isn't flowing uphill
it needs the pressure generated by pushing against the closed end to come out of the holes so until it reaches the end the water just rushes past the holes

 

[John S]

Thanks. Will try blocking alternate holes and see how we go.

 

[John S]

OK, I've fiddled around with masking holes. It's better but not great. What I can say is that all the plants have some gentle movement on them. Will this be OK I do I need to keep working with the uniformity?

 

[Alastair]

If all the plants have a nice gentle sway that's fine, it's as plant mass increases that you'll need to keep an eye on how effective it still is

 

[John S]

If all the plants have a nice gentle sway that's fine, it's as plant mass increases that you'll need to keep an eye on how effective it still is

Thanks Alastair. I had a further look at both pieces of spraybar tonight and noticed that the original 2078 300mm spray bar, which is it the far end of flow, has 4mm holes. The new 400mm section, which is closest to the pump outlet, has 3mm holes This obviously hasn't helped

 

[Alastair]

Try them both at 3mm