tyrophagus
Member
I'm suprised its taken me so long to measure the flow from my filter. I've read over and over that I need good flow and I understand why. I assumed that having a rate 1700lph filter would be enough even though I expected the actual flow to be a lot less. Recently I added a small external eheim that previously lived in the loft that's rated 650lph.
Is the 10x tank volume rule based on rated or actual flow?
At water change day I decided to measure the flow at the spraybar. I collected 7.2 liters in 1 minute so that makes a flow rate of 432lph which is 25% of the rated flow for the filter.
No wonder I'm battling algae and my crypts keep melting! In my setup the hardscaping creates 2 barriers that run above the substrate for the length of the tank. This complicates my flow issues but at present I have most of the plants gently swaying in a breeze. It must mean that I'm not distributing the co2 properly despite having a yellow drop checker (10 bubbles per sec!!!)
So why 432lph? I have sintered glass in all three chambers, none are full. I've removed the filter floss before measuring flow but there is the eheim "prefilter" or is it post filter sponge. The spray bar is a few feet above the filter. The outflow travels through a sera CO2 reactor and then through an external heater (hydor). I think there is just to much in the way!
I have not measured the flow without the heater and reactor. (I will once I've change the setup)
So my plan is to keep the heater and co2 reactor but drive them with an eheim compact+ 3000 pump installed externally. The pumps rated at 3000lph max so even if I get the same attrition of flow it should provide 750lph and given there will be no filter media in the way the flow will probably be higher.
I'll then use my 2076 as the filter but have nothing installed in the outflow pipe to obstruct flow so that I hope will improve substantially, perhaps even reaching 1000lph.
That should bring me closer to the flow I need.
No wonder I'm pumping co2 into the tank and still having problems. Clive and other wise posters said flow, flow, flow and I just assumed my flow would be adequate from the published rates for the filter. Perhaps the lesson is that if you are having trouble measure your actual flow rate.
Is the 10x tank volume rule based on rated or actual flow?
At water change day I decided to measure the flow at the spraybar. I collected 7.2 liters in 1 minute so that makes a flow rate of 432lph which is 25% of the rated flow for the filter.
No wonder I'm battling algae and my crypts keep melting! In my setup the hardscaping creates 2 barriers that run above the substrate for the length of the tank. This complicates my flow issues but at present I have most of the plants gently swaying in a breeze. It must mean that I'm not distributing the co2 properly despite having a yellow drop checker (10 bubbles per sec!!!)
So why 432lph? I have sintered glass in all three chambers, none are full. I've removed the filter floss before measuring flow but there is the eheim "prefilter" or is it post filter sponge. The spray bar is a few feet above the filter. The outflow travels through a sera CO2 reactor and then through an external heater (hydor). I think there is just to much in the way!
I have not measured the flow without the heater and reactor. (I will once I've change the setup)
So my plan is to keep the heater and co2 reactor but drive them with an eheim compact+ 3000 pump installed externally. The pumps rated at 3000lph max so even if I get the same attrition of flow it should provide 750lph and given there will be no filter media in the way the flow will probably be higher.
I'll then use my 2076 as the filter but have nothing installed in the outflow pipe to obstruct flow so that I hope will improve substantially, perhaps even reaching 1000lph.
That should bring me closer to the flow I need.
No wonder I'm pumping co2 into the tank and still having problems. Clive and other wise posters said flow, flow, flow and I just assumed my flow would be adequate from the published rates for the filter. Perhaps the lesson is that if you are having trouble measure your actual flow rate.