Backyard Aquaponics
A place to discuss aquaponics

If you haven't got everything glued together yet, you could reconsider your distribution system to the GBs. In your current configuration, you're controlling the equal flow of water to each GB by having to "precisely" adjust the valves, but you can achieve an equal flow to every GB in a system if you let gravity and a little bit of fluid dynamics do the work.



So long as the vertical risers have the same diameter and length (resistance) the flow through each, and therefore the flow into each GB, will be (very nearly) the same. I used 90mm for my manifold (previous system) with 25mm risers (the larger the manifold, the more equal the distribution?). You can still use valves to isolate each GB (recommended). Total flow to all GBs is adjust using the throttle valve in the drain.

The manifold should be positioned below the top of the GB, so each riser "rises" vertically to the height of the GB.

0.02c or maybe something for your next system/upgrade? The manifold will work (within reason) for any number of GBs.



Scott

P.S. For any engineers out there -- I know the volumetric flows wont be precisely equal, I've had the very loooong lecture from my Dad; please, let's just assume close enough is good enough to equality for these purposes!

Thanks Scott. As you can see in pics, I have essentially what you have drawn above; Pump/T to FT/Outlet1/Outlet2, except it's all the one diameter (25mm). And yes, it's all glued solid!!

I was having trouble throttling and controlling the flow from O1 and O2, particularly with the powerful pump, but adding that T prior to O1 seems to have fixed that issue. I have O2 (furthest from pump) ever so slightly throttled back to keep a little more pressure at O1 and, as you put it, close enough seems to be good enough so far. Both GBs are filling pretty much at the same speed, but even if they fell out of unison, I don't know if that would be such a bad thing. If anything, it may mean a little more water in the FT during cycles...

As with anything, and as with anyone jumping into this hobby, it's going to be a learning curve. At this stage, the plumbing seems to be working very well. If I experience loss of flow from O1 and O2, I have a lot of play in the T-off valve to give more pressure when needed.

Thanks again, Scott. All advice happily accepted

I guess another learning point of conjecture is the use of glues (cannot be undone, but really strong against high pressure) vs. silicone (not as strong as gluing pipes together, but can be undone it needed by using a bit of force) vs. pressure is not that great so why bother gluing/siliconing anything (might not be the case in your circumstances with am 8000lph pump and 25mm pipe!).

Another view: glued joins cannot be tinkered with, siliconed joins impede but do not prevent tinkering, and never glued joins are an invitation to keep changing things!

Maybe in your next system (upgrade) you may or may not decide to glue, this will probably depend on the lessons learned from this system?

Equal flow into the GB is really only desirable (not mandatory) for the equal distribution of solids from the FT. There is no harm in having your siphons firing out of synch (on the contrary, depending on the configuration it may be more beneficial to have your siphons out of synch so that water is returning to the ST/FT more frequently than a lot of water suddenly returning to a tank with "extreme" low tide).


Scott

I had never considered silicone...only ever used silicone products for two things: building aquariums; and lubricant. Lol.

Again, time will tell whether I have made the right decision to glue, but I dunno... You are dead right that gluing ruins any hope of future adjustments, but I think I would definitely continue to glue in the future as well. The idea of bits and pieces suddenly flying off under extreme water pressure does not sit very comfortably, lol.

Just went home for lunch and everything is still kicking along nicely. GBs fill, siphons fire, GBs drain, siphons break, repeat. Pretty happy that it's all kicked off first hit. Fingers crossed for a trouble free cycle, fish introduction and harvest of veggies!

Try that vid post again...

So it's getting into winter here and I am starting to think of tank heating. Cairns winters usually see maximums of around 25deg during the day and coldest of around 11...although average overnight would be nearer 16 or 17 across the season. Since my FT is buried, I am really hoping that my plan for thermal stability will pay off. However...what sort of heating do you all have in place? I am considering buying 3x300W heaters at about $30 each, but is that the way to go?

What I really would like to do is make a solar heating system using a roll of 19mm poly pipe, a box or two of elbow fittings and a small pump, timed to run for five or ten minutes every four hours (say 10am/2pm/6pm). I'll cut and connect the poly pipe into a zig-zag type arrangement and sit that on top of the awning above my system. I'll also install a one way valve to prevent water siphoning back to the tank when the pump is off. I really like this idea, but what do you think? Viable? Any experiences??

If you upload your videos on YouTube (or any other non-Flash site) then people using iPhones, iPads and non-Flash capable browsers will be able to watch.



Scott

And you can embed the Youtube video within a post....

Lol, I love how crApple is non-Flash capable. Stupidest thing ever. Just because Jobs decided to have a little hissy fit at the Adobe people (or vice versa), everyone that's forked for an overpriced phone or computer now has to suffer. My solution? Android. More specifically, HTC OneX. Beautiful piece of gear and Flash compliant as well!

Anyhoo, I get the point. Have never really uploaded to YT before though. I'll look into it...just for all the sad iSheep out there

In the meantime...what of my heating dilemma??

Why do you need to heat... in FNQ???

For the reasons mentioned above.

I'm not sure if I need heating, but I will be stocking with barra soon and I have read somewhere here they tend to get sluggish/stop eating/die at below 20deg. As I said, I'm really hoping the sunken FT will stabilise my temps, but I'm just considering options...

I wasn't using my iPhuck when I posted, I don't allow flash to run on my browser either!


As for heat in Qld? You're kidding right?!
http://www.weatherzone.com.au/climate/station.jsp?lt=site&lc=31011
http://www.bom.gov.au/climate/averages/tables/cw_031011.shtml


Scott

Small update.

I decided to re-route my electricals, so now rather than running along the top edge of the upper cross beam (as can be seen in pics), it is now slung along the bottom edge of the lower beam, right out of the way. Happy with it now, looks much tidier.

I have fish! Bought some barra on the weekend and they seem pretty happy in their new digs. I only got ten to begin with and will add ten more in a week. I also bought an air pump, a 35L/min magnetic ReSun. Not the best brand, but has 12 months waaranty so I'll see how it goes.

The lone tomato plant has some friends...and some fruit coming through. I've added Pak Choy, Celery, Lettuce, Beans and Broccoli to one bed and Mint, Basil, Coriander, Spring onion, Thyme and Parsley to the other. The beans and celery were both seed sown...am sure I've read it possible to grow from seed, but am I right with that?? Need to think of other things I can add...

Otherwise, all hunky-dory. As I posted in my "CF-ers" thread, I managed to fix the faulty siphon, so the system is FDing like a trooper.

Cheers.

I guess one of the cheapest (running) ways to heat would be solar and maybe also using a refrigeration system for stability at night. A bazillion times more efficient than electrical resistance heaters (since it is a heat Pump, not a heat creator), but also a bazillion times more in capital outlay

I was thinking more like a coil of black poly-pipe, a pump and a timer set to five minutes at about 6pm would be the way to go... Let the water heat during the day, then pump it into the tank, drawing fresh water out, in the evening. It'd just give that touch of warmth to get thru the (relative) cold of night... But anyway, was just a thought.

Salt. Did a bit of searching, is 1kg per 1000L about right? And how often will it need to be topped up? No, I don't have a refractometer...