SLO or External Standpipe - Fish Tank to Swirl

[Shawn G]

Hi,

First post.  

I know that an SLO is the standard way to get solids laden water from the fish to a swirl filter, BUT, would an external standpipe work just as well?

I am planning on a fiberglass/wood 500 gallon tank leading to a vortex filter made from a plastic 55 gallon drum.  Water movement is planned to be 10 gallons per minute.

A 2" standpipe cut at the desired tank level would be inside of a taller a 4" pipe and go on to the vortex filter (2" pipe connecting to the vortex - I typically see 4").  Going upstream from the cut standpipe I end up at the tank drain which is set in a "dish" - the floor of the tank is sloped to this "dish" and I am hopeful that the majority of solids will gather here.

I could go with an SLO, but it seems that, since I need a tank drain anyway, if I divert drain water to an external standpipe I would achieve the same objective and the finished install would be a little cleaner.

Your thoughts and direction are appreciated :)

All the best!

Shawn G.

[George]

You could consider an air lift to move water out of your fish tank.  Not sure if you could achieve 10 gallons per minute but maybe.  I don't know what a drain tank is, nor external standpipe.  Can you control the water level in your tank with an external standpipe?  That's what a SLO does, overflows at a given level.

Look at the external siphons at Olomana Gardens.  I don't use siphons so I can't speak to it much but it looks interesting.  Glen uses air lifts for moving water - no pumps.

just food for thought

https://youtu.be/c9B9c_QLD-E

[Averan]

Sure, of course you could. It would still be a SLO, just external. Whatever works best for your needs. Center drains are great in round tanks.

[Shawn G]

Thanks Guys!

I'll give it a go!

[Jeff S]

I'm assuming your FT will have a drain similar to an IBC. If so DON'T use the tank drain for solids removal. After having a solids drain hooked up that way to my IBC I have just changed it. It worked fine to remove solids but I was in constant fear of a catastrophic leak that would drain the tank. Plus the smaller fish were swimming up the drain to the filter. Also I was always having to clear it inside the FT with a plunger through the swirl filter. I put my SLO in at the same lower spot in the tank at the drain. I love the way it's working now.

[Shawn G]

Heya Jeff!

Not sure what you mean by a drain similar to an IBC because I am not super familiar with them - I plan on installing a shower drain (or the like) in the bottom centre of the fish tank.  It would be needed should the need arise to drain the tank, but more practically provide a point at the low low point to capture/drain out solids.

The 2" drain pipe will Tee to a closed valve for tank draining and continue on to a 4" external standpipe with a 2" internal pipe that provide overflow / tank level setting.

Makes sense?

Sound Good?

Thank you for taking the time to respond, eh.

Shawn G.

[Jeff S]

The bottom drain is a good idea however you can pump the tank empty if needed. The only reason you would ever drain your FT would be if the fish all died and hopefully that will never happen.  The drain being used as the solids removal invites a way to accidently empty your tank. The SLO positioned in the lowest part of your tank and going out the side of your tank at the preferred level in the tank is your best option. Look in "groups" tab and go to IBC Aquaponics group. There's a lot of good information about plumbing options with the IBC tanks that can be applied to any setup. Check out Jim Fisk's info and pics.   http://community.theaquaponicsource.com/group/ibc-aquaponics

[Shawn G]

Hello again Jeff.  I'm going to adopt most of your suggestions (Why deal with a drain when I may pump once every... 10 years?) and create a variation on Jim Fisks SLO design.

Brilliant.

Thanks for the direction!

[Jeff S]

Here's a couple of other good info sources: http://community.theaquaponicsource.com/profile/VladJovanovic    Seems to really know his stuff.

Also Bright Agrotech YouTube videos. Good basic growing information.