Filter Flow and Reduction.

Discussion in 'Filters, Filtration and Pumps' started by GreenNeedle, 29 Mar 2008.

  1. GreenNeedle

    GreenNeedle Member

    Messages:
    2,706
    Location:
    Lincoln UK
    The basic point of this thread is after using the powerhead (trying out the needlewheel principle) in my tank rated at 400lph (reduce some for the holes) I noticed how weak my filter flow must be!!!

    My filter is the Tetratec EX700 (700lph) The only media it has in it is ceramic rings occupying half of the bottom tray, 1 foam pad in the second to top tray and 2 in the very top tray. This means it only has half of the media in it that it should which I assume will mean that it reduces less of the flow.

    Then it runs into a UV steriliser and then onto the external heater. Then onto the tank as per normal.

    My question is that when I clean the pipes including the hose conns into the filter fortnightly. Should my flow be reduced by so much?

    I am thinking of disconnecting my UV at the moment to reduce the length of hose and also the amount of 'obstacles' in my output.

    The inflow has nothing between the tank and the filter apart from bloody MTS which keep getting stuck in the holes.

    Thanks in advance for replies.

    Andy
     
  2. Steve Smith

    Steve Smith Member

    Messages:
    4,428
    Location:
    Leamington Spa, UK.
    Yeah, I hate that. I get exactly the same on my EX700. I have all of the media in mine. I might reduce it somewhat, as I have a Fluval 204 on the same tank (with reduced mechanical media). I might just take out 2 of the sponges and replace with more bioballs. Mine also goes through a UV steriliser but not an external heater. If I ever go for an external heater I'll probably put it onto the Fluval instead.

    Have you checked the impeller shaft for gunk?
     
  3. GreenNeedle

    GreenNeedle Member

    Messages:
    2,706
    Location:
    Lincoln UK
    Yep I clean the pipes and the impellor and the whole filter monthly (not fortnightly as I posted above. don't know what I was daydreaming about there.

    I do 10% (1 bucket) water changes twice weekly just to remove detritus and then monthly I clean the pipes, the inside of the heater, the inside of the UV, the inside of the filter/impellor and the media.

    I have just removed the UV from the chain which also reduces the travel distance from the filter to the tank by about 2½ feet. I must say it looks a darn sight faster.

    Maybe its not the UV but the distance?

    andy
     
  4. Ed Seeley

    Ed Seeley Member

    Messages:
    3,262
    Location:
    Nottingham
    Every length of pipe will reduce the flow rate as the water is restricted so the shorter the pipes the better.

    As far as filter media goes you can fill the filter with non-restrictve media (like open void media or sintered glass with plenty of water spaces) as this will only marginally slow the flow. Foam, especially once it starts to block, will cut the flow significantly though, even as one layer.

    The UV will have seriously reduced the flow as they tend to have pipes coming in at almost right angles thereby creating quite a lot of turbulence and reducing the flow. I'm thinking of taking mine off my pond for the same reason as it's hardly ever turned on.
     
  5. GreenNeedle

    GreenNeedle Member

    Messages:
    2,706
    Location:
    Lincoln UK
    I'm thinking of selling mine now. Shame I can remember how proud I was to tell people I had the latest Vecton when I got it less than a year ago but with crystal clear water, no sign of disease and minimal algae I can't really see the point of it.

    I remember some plonker telling people on another forum a while back that you had to leave UVs on for 24/7 or you would get algae. Without thinking I switched mine back on (was running it at night only).

    Now I think about it properly if it isn't on there is no light and therefore.....I feel a little silly now. lol

    Anyways...Off to the for Sale section.

    Wish I'd bought a EX1200 now. lol. Still I do have a filter capable of 5.6 throughput.

    Andy

    Andy
     
  6. beeky

    beeky Member

    Messages:
    879
    Location:
    Chippenham, Wiltshire
    Surely a UV needs quite a slow throughput so the light has time to do its thing? Maybe that's why they have right angle inputs.
     
  7. Steve Smith

    Steve Smith Member

    Messages:
    4,428
    Location:
    Leamington Spa, UK.
    I totally know what you mean. I wish I'd gone for the 1200 now. Still, am using the 700 and a FLuval 205 (replacing the 204, not that it will make any difference!) so I guess its good enough.
     

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