Quote:
Originally Posted by scolley
I've got to agree, and disagree, Steve. I find that even my brand new cartridges that they start out somewhere around 3 psi, and climb to 5 within a few months, and with 3 or 4 months are at 7 and climbing. My Poseidon cuts out at about 10 psi, with flow really diminishing once it hits 8.
Assuming that a "high head" pump is what is otherwise referred to as "pressure rated" pumps, I'm in full agreement. But unless I'm missing something, the Poseidon PS1 and PS3 are their pressure rated pumps, not the 2 or 4.
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You're getting much longer life out of your pleated cartridge than I am. No doubt this is
mostly due to the QuietOne pump I'm using which has a much lower cut-off head than your PS1. With a new cartridge and no disturbing of the substrate in my 90-gal by moving plants or re-scaping, the 25 micron might last one month before it has to be cleaned/replaced. And of course after being bleached and cleaned with a high power pressure washer it will only last about 10 days before needing to be cleaned again. Not very cost effective or fun.
Click Here for the complete spec sheet on the Poseidon pumps.
-- Poseidon pump Flow vs. Pressure chart from the spec sheet --
Quote:
Originally Posted by scolley
Well here's some anecdotal, not proven, information.
Here's a Poseidon.
And here's a Velocity.
They look the same. Right? Same specs I believe.
Well my first pump is a Poseidon PS1. And for my 2nd pump I bought a Velocity T1. Should be the same. In person they look the same.
Well, that T1 definitely adds heat. I've been battling that since I installed it. During the day I only let it run 15 minutes out of every hour. Otherwise the tank warms up.
Now, it's entirely possible that the PS1 is really heating the tank up, and that the T1 is just the straw that broke the camel's back. But I'm not so sure. I know that the PS1 is adding some heat. But he T1 seems to be adding more. I'm not sure what the difference is, but I suspect there is one. And it could well be that the Velocity's propensity to add heat has given the Poseidon's a bad rap because everyone thinks they are the same.
I can't prove the Velocity is adding more heat. Would love to do an experiment. It's easily done... turn off the heaters, lights, UV and pumps, let the tank chill to ambient temperature, then turn on one pump. Wait for the temp to peak, and measure the difference between tank temp and ambient temp. Then repeat the whole process with the other pump.
But right now in Connecticut ambient temp is a bit cool. I'll have to wait until it warms up. |
The heat issue is a major factor for me because my tank is in a room that stays near 77~78 degrees during the day and maybe drops to the upper 60s at night. The water temp is usually between 78~80 deg F most of the time. Adding a pump that could potentially raise it another 4~6 degrees would be a kiss-of-death without adding a chiller.
Your proposed experiment to measure the rise in water temp caused by the Poseidon PS1 and/or Velocity T1 would provide excellent info for anyone considering using one or the other in a pressurized cannister setup.
Quote:
Originally Posted by scolley
Thanks for the info Steve. It is that 318 set that I got too. But haven't used it.
In principle the a 318 and 340 should be used in series, in that order. But since I have two separate filtration paths, they run parallel, and the 340 - which should be primarily polishing - is also doing normal mechanical filtration. So it doesn't last nearly as long without maintenance as it otherwise might. That was a design compromise that I accepted up front.
So in my own situation, the 318s may be easier to clean. And the 318s may go longer between cleanings. And they definitely have a much larger biofilter capacity. But they can't filter any better than the 340. So as long as I believe my biofilter is sufficient (as I do now), I'm going to opt for the higher level of filtration over ease of maintenance and potentially reduced cost.
But I'm glad to hear that the 318 looks like a good option. Thanks! I'll keep those spare filters handy!
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With all of the other plumbing and electrical equipment housed in the stand on my 90, there just wasn't enough room to accommodate a second cannister filter. Time for a bigger tank
With the 318 media in my cannister, it was about 3 weeks before the water started looking fairly well polished -- not quite at the level of the micron cart yet though.
Your ability to run two filter paths with different media is a definite plus. It should really extend the period between cleaning/replacement of the media.
Really appreciate all of your feedback on the pumps and filters.
Steve