Backyard Aquaponics
A place to discuss aquaponics

I was planning on doing a CHOP2 style IBC's for my AP setup but i'm starting to rethink that. I have a few questions about constant flow and SLO.

When setting up a constant flow, do you use just a straight standpipe that is plumbed from the bottom to the height you want the water to drain at? Does this pipe have multiple holes in it to allow water to drain at all levels? I was introduced to AP's from Murray, like so many, he sold me on the flood and drain concept. I like the idea of having a constant water level in the sump.. this would make topping off much easier. Can someone show me a diagram that shows the exact plumbing or is it that simple?

SLO - I've spent at least two hours trying to research and find a thread that explains this concept as well as design and have come up short. The phrase "SLO" is in a ridiculous amount of posts and I have given up on trying to find answer to my questions about it. Can someone break down the concept and design for me? I understand its the means of bringing water from the FT to the GB's but how does it work and what are it's benefits? I've read from a few threads that's a 3" PVC is recommended? ...someone please help me out.

My CF beds have a standpipe w/o holes. The water flows up to the appropriate height, then falls through the standpipe. Simple, beautiful.

Solids Lift Overflow. It's easy to plumb so that water flows from one tank to another, but how do you transport solids (fish poop) from the bottom of one tank to the top of another? SLO! The idea is a pipe that sits on the bottom of the fish tank w/ slits cut in the bottom. This pipe is plumbed up to the top of the next tank, so as more water enters the fish tank, pressure pushes water and solids into your pipe and the tank overflows through this pipe bringing the solids with it and to the top of your grow bed. I have heard that large pipe is recommended. Don't remember how big. I've never built one, but researched them before building my system, then read a lot of posts here.

Okay, so a SLO is a means of getting the waste from the bottom of the FT to the grow beds? That sounds simple enough. So, a SLO would work sort of like how a baffle works? Would the height of the FT water have to be the same height as the outlets to your GB?

Correct. The height at which the SLO releases the water will dictate the water level in your fish tank. You could have it come out at the bottom of the fish tank, then go up to the proper level and over or have it come up inside your fish tank, then exist at the level you want the height of the water.

I don't know what a baffle is, please educate me. Probably not the below (an option wikipedia gives). Though I suppose you could have a SLO shaped like a dragon or something =).

Baffle (architecture), a structure designed to confuse enemies or make them vulnerable

Baffles are used in fish tanks to control the flow and height of the water... they are used mainly in sumps. Having a PVC pipe run from the bottom of a tank over to the top of another kind of reminded me of the concept.

Good to know. Thanks.

Hello seanmc980,

I thought maybe a picture might help conceptualize a SLO concept.

In the picture below, a vertical pipe goes to the bottom of your container. At the bottom of that tube are a number of holes or slots cut into the tube for the water to enter. Because of the weight of the water above, water and solids are pushed up the pipe to an inline tee. If you look close enough you will see the top of the tee barely poking thru the gravel. Then water and solids flows out the buried tee thru the wall of the container to where you want it to go.

Another way to use a SLO is out the bottom of a container.

In this case there are 2 vertical pipes. The first pipe is plumbed thru the bottom of a container. It more or less acts as a stand pipe holding the water at a constant height in the container. A second larger pipe slips over that stand pipe and has slots or holes at the bottom of it. The weight of the water above pushes water and solids thru the holes and up between the 2 tubes. Water and solids then over flow down into the inside pipe (stand pipe). Once thru the bottom of the container the water and solids can be routed to where you want. In this application the water and solids are plumbed from under the container and up to the top of the next container. In this particular application the difference in height of the internal stand pipe and the outside of the container pipe is about 4 inches. This seems to work well in this case.

I have not experimented with tweaking the height differentials.

Other people more experience than I can discuss and fine tune the different heights of the 2 pipes in the tank and the pipe out side the tank.

Hope this helps.

Hello seanmc980,

If you would like to see some pics of a SLO take a look at my system thread.

There is also a thread on here somewhere by TCLynx which has plenty of diagrams and explanations.

Here is the link: viewtopic.php?f=11&t=5311