Solids handling, pumps and small scale

[sarumont]

I've been running a small-scale AP system inside for about 8 months now. I've learned a lot in that time from the system and these forums (thanks!). I'm now facing some issues with my pump and/or line to the GBs getting clogged. I actually just cleaned out that line, and I found quite a bit of algae growing (and it's a black poly line!).

My larger concern, however, is the pump. It will get clogged to the point where it does not pump enough water to run both autosiphons. At this point I fear it's beyond recovery - I've cleaned it to the best of my ability (but its innards are not accessible), and it's not pumping enough to run both siphons.

This has me looking at new pumping and solid solutions. First, I'll describe my system quickly. I have a 14g (53 litre) FT with some goldfish (mostly the 25-cent feeders!) pumping to two GBs that are about 18"x24"x6" (lxwxd) (about 11.2g or 42.4 litres). Both are configured with autosiphons using a 1/2" (12.7mm) standpipe. I have a submersible fountain pump I picked up at Lowes which (I think) is rated at 170gph max. Given the 2' head, it's probably pumping around 100-125gph, though I don't have anything to measure the flow rate.

Ideally, I'd like to get a pump that just passes the solids, so I can add a filter to get rid of them. In my searches online, however, it would seem that the smallest pump that specifically states a solids-handling capacity is the Laguna Max-Flo 600. 600gph is quite a bit more than I would need, but that doesn't bother me as much as the size.

Does anyone have any suggestions for either a pump fitting my system or a pre-filtering technique I could employ to keep solids from gumming up my pump?

Thanks!

[GaryD]

Hi Sarumont,



I've been running a small-scale AP system inside for about 8 months now. I've learned a lot in that time from the system and these forums (thanks!). I'm now facing some issues with my pump and/or line to the GBs getting clogged. I actually just cleaned out that line, and I found quite a bit of algae growing (and it's a black poly line!).

My larger concern, however, is the pump. It will get clogged to the point where it does not pump enough water to run both autosiphons. At this point I fear it's beyond recovery - I've cleaned it to the best of my ability (but its innards are not accessible), and it's not pumping enough to run both siphons.


When I first started out with smaller aquaponics systems, I found that even 12mm tubing quickly became clogged up with bio-film. I used to resolve this by blowing hard back through the pipework. All of the built-up muck would blow back through the pump and restore its pumping ability.

These days, I wouldn't bother with any pipework which is less than 19mm or 3/4".......and most of it would be 25mm - 40mm.....for reasons you're discovering.



Ideally, I'd like to get a pump that just passes the solids, so I can add a filter to get rid of them. In my searches online, however, it would seem that the smallest pump that specifically states a solids-handling capacity is the Laguna Max-Flo 600. 600gph is quite a bit more than I would need, but that doesn't bother me as much as the size.

Does anyone have any suggestions for either a pump fitting my system or a pre-filtering technique I could employ to keep solids from gumming up my pump?


Your other option would be to incorporate a sump tank into your systems (on the discharge side of your grow beds) and place your pump in that. That way, all of the settleable solids will have been removed before they get near your pump. This constant height/one pump (CHOP) arrangement in increasingly common around small aquaponics systems but it's been a feature of commercial systems (like the UVI one) for many years.

Solids removal in a small system like yours can be as simple as placing an orphan sock over the outlet from your fish tank. This can be quickly and easily removed for cleaning and will capture much of the solid material from your fish tank.

Gary

[sarumont]

When I first started out with smaller aquaponics systems, I found that even 12mm tubing quickly became clogged up with bio-film. I used to resolve this by blowing hard back through the pipework. All of the built-up muck would blow back through the pump and restore its pumping ability.

These days, I wouldn't bother with any pipework which is less than 19mm or 3/4".......and most of it would be 25mm - 40mm.....for reasons you're discovering.

I very quickly discovered that smaller systems are (theoretically) less-forgiving in pretty much every way. Alas, I'll be limited to small-scale for awhile.


Your other option would be to incorporate a sump tank into your systems (on the discharge side of your grow beds) and place your pump in that. That way, all of the settleable solids will have been removed before they get near your pump. This constant height/one pump (CHOP) arrangement in increasingly common around small aquaponics systems but it's been a feature of commercial systems (like the UVI one) for many years.

That would work well, though I'd have to re-architect the system a bit. Everything is stacked currently with the GBs on top (pics can be found here: http://gallery.sigil.org/apartment_aquaponics/).


Solids removal in a small system like yours can be as simple as placing an orphan sock over the outlet from your fish tank. This can be quickly and easily removed for cleaning and will capture much of the solid material from your fish tank.

I may try a sock around the pump itself, as solids in the pump are more problematic right now than solids in the plumbing. I've also had success with a fish tape and some cloth to clean out my plumbing (I have flexible poly tubing from pump to GBs).

I may end up grabbing one of the pumps I found which has a replaceable/cleanable filter built into the intake. Much easier to clean that than the pump and plumbing. :)

Thanks, Gary.

[GaryD]

Hi,


I may end up grabbing one of the pumps I found which has a replaceable/cleanable filter built into the intake. Much easier to clean that than the pump and plumbing.
Those filters are the first thing that I dispose of when setting up a new pump - they block up really quickly.

Have you contemplated sitting your pump up off of the tank bottom? That would help to stop it from catching so much gunk. You could syphon any solids that accumulate on the tank bottom.

Gary

[sarumont]

Hi,


Those filters are the first thing that I dispose of when setting up a new pump - they block up really quickly.

Have you contemplated sitting your pump up off of the tank bottom? That would help to stop it from catching so much gunk. You could syphon any solids that accumulate on the tank bottom.

Gary

d0h! Glad to know they suck before buying one, though.

I moved it off the bottom awhile ago, and that seemed to extend the time between required cleanings. I may move it up a bit more and point the intake into a corner rather than the main part of the tank to see if that helps any.