Backyard Aquaponics
A place to discuss aquaponics

Hello everyone,

I was wondering what size and how many holes you guys have drilled in the bottom of your SLOs. Also I remember seeing someone's design that had a T connection at the bottom of their SLO and branching out so that it could collect waste from the parts that extend out too. I was wondering if this is a good idea or not. Will drilling too many holes affect the suction action at all?

I use 90mm pipe. It goes from one side the other of my 5000 litre tank so is about 3 metres in length.

Every 50mm I have a 5mm slot which I used an angle grinder to create.

Here is the SLO across the bottom of the tank:


Here are the slots:

Thanks Arbe, I like your design. Do you think the slots could be substituted with drilled holes and have the same effect?

A standard for drains in recirculating aq systems is to size the holes so that the velocity is less than 30cm/s.

Slots are better because they are less likely to block and easier to clean if they do.

IV got 2 ends that i put on my slo, 1 has 10mm Slots, the other has 7mm Holes, the one with holes is for when iv got fingerling in there and then i swap it over once the fish are big enough to not get sucked through the 10mm slots.

You dropped some bits in your tank Arbe......

You could. You would just need a lot more holes to obtain the same amount of flow.

@EB. I have fished them all out now. They were in there for the gold fish to hide in, in an attempt to keep the mozzies from breeding.

Sorry, I think I might be hijacking this thread

Arbe, do you ever get fish sucked into the SLO?

I've never checked. I would count the fish to see if they are all there but they are too quick.

I will say I was concerned that may happen but when Troutman delivered them I showed him the design and he did say it wouldnt be a problem.

Cool, trout deliveries and system advice at the same time....