What is the ID of your return plumbing?
What is the ID of your return plumbing?
Originally Posted by Floyd R Turbo
About 22mm I think, it's 25mm (about 1 inch) pipe
Actually, now I think of it, there is a hose joiner thing on it which probably restricts it further. I'll have to have a look at that and see.
Thanks Floyd, you might have saved me getting a new pump!
It's a common problem that comes up when you build a scrubber. Unless it's critical for your tank (like heavy SPS) most people think their flow is fine, when it's really not. The Mag 12 I was running should have been pushing 1100 GPH but was only pushing 433 with a clean pump. I was running 3/4" return, upped it to 1.25" (still a 3/4" bulkhead) and it went to 780. It's simple fluid dynamics, the smaller diameter pipe, the faster the water has to move through the pipe, thus more friction and reduced flow rate. Head pressure on the pump is not a function of the diameter of the piping, it's a function of pressure. The weight per horizontal square inch of water in a given water column height does not change, only the square inches itself. This means that the calculated head pressure resulting from a given column of water, ignoring friction, a 4" PVC pipe is identical to that of a 1" pipe. You can put the biggest plumbing you can feasibly install.
Just took the hose off & measured the connector ID
It takes it down to 15mm -vs- 20 mm for the rest of the plumbing
So that will be going tomorrow.
Thanks again Floyd.
That is definitely your problem. Bump that bad boy way up, you'll be shocked.
Yes throw out anything dead.
Dunnit.
The flow from the Ehiem is now about 2050 lph, which is not far off that Eheim claim (I misread the chart, it should be giving about 2300 at this head)
So I have 2050 from the display plus 900 from the chiller return totalling 2950 litres per hour across a 56 cm wide screen giving 53 litres per hour per cm
Which is 35 US gallons/hour/inch or 29 imperial gallons/inch. Should be ok I guess.
Thanks again Floyd, saved me buying a new pump.
Went away for a week, did a clean the day we left (Sunday before last) and was expecting some nice growth on my return.
Was a bit disappointed.
There was growth, about the same yield as the previous week, give or take, and a few patches of longer tougher algae which I hadn't seen much of before, but most of the algae was very light green and soft/slimy, not quite yellow, but washed out green.
The tank wasn't fed while we were away so I guess that's an factor but there is some type of hair algae (or maybe green cyano?) in the tank (that nothing will eat) which I was hoping 7 days without food would reduce either by starvation or by the herbivores in the tank being forced to eat it in the absence of anything else. But it has actually increased while we were away, by quite a lot.
Didn't take any pictures as the battery was flat when I cleaned.
Anyhow, I've read on here that pale green can mean low iron so I've put an iron nail in the sump & will monitor what happens with that.
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