Backyard Aquaponics
A place to discuss aquaponics

Nope... well maybe around $600... [/quote]


http://nano-machinery.com/catalog/produ ... cts_id/537

I've been looking at this one

Woops! sorry rupe, missed your post.
Thanks for re-posting all that info, much appreciated.

Might actually get the pro test kit as it would be another aspect I can learn about that may actually help with my horticulture knowledge, which is always a bonus!

Thanks for the link gnash - looks good They are still BLOODY expensive tho arent they!

Should have solarweave and shademesh this week. If so we will be busy this weekend!

Vinegar tested my media this morning. River pebbles are fine but quartz is fizzing quite nicely unfortunately

A bit dissapointed actually, if nothing else they were a fair bit lighter than the river pebbles, not to mention the fact that they were gemstones, and looked pretty!!! sorry... had a girly moment there... wont happen again. (actually I make NO promises)

Just be a little wary of those pH strips.... they've been reported to be inaccurate, especially as they age...

Havent posted for a while but everythings happening quickly now! Just read from the start and realised weve modified a bit since then. We are going to have 3 banks of 7 half cut IBCs plus 2 banks of 8 yabby/growbeds which we will start off all filled with yabbies and maybe fingerlings to get system cycling before we start filling the tanks. Once we are cycling nicely and fish start growing, we will be pulling out yabbies from the top growbeds and filling with gravel to increase growbed ratio. Hopefully this will work!

Now for the pics...

Put the roof up today so will have more pics tomorrow.

Heres the volumes we will be working with - thoughts welcome.

With the 16 x 1000L IBCs cut down we estimate that they can hold around 750L, bringing the total for the IBCs to 12,000L. Add the 6,500L and we have 18,000L of tanks going at the start!

The 3 banks of half cut IBC growbeds we estimate will fill to 450L volume each x 21 GBs = 9,450L. Once the top half of the yabby IBCs are converted over to GBs that will convert 4,800L from tanks to GBs which will make it - 13,200L tanks : 14,250L GBs.

I know its pretty close to 1:1 ratio and we were originally aiming for 2:1 but we are hoping that because the yabbys are at such a low stocking density, they will not put much load on the system, plus the increased water volume should help to stabilise the system anyway. Working on this theory I am wondering whether if we kept 8 yabby setups as all tanks and grew duckweed on top instead of turning into GBs, if that would also help even out the load allowing for those tanks being kept?

Would appreciate any thoughts on this as I am a little worried about our ratios. Seems ok to me but am interested in ideas on how heavy the yabby load will be if some IBC tanks have 10-15 to grow out, and the rest have breeder pairs!

Just to clarify the last post, the 16 'cut down' IBCs are the 2 tier yabby tanks. We reckon that they will hold about 300L in the top and 350L in the bottom. These 16 yabby 2 tier tanks will total 12,000L.

The 'half cuts' are just GBs sitting on the ground which we've estimated would hold about 450L ea when leaving a gap at the top, and are 3 banks of 7 GBs = 21 GBs.

so 13200L FT, 9450L of GB and 4500L of yabbie tanks right?

ypu might be better of stockign yabbbies a little denser in to botton half, and turingin the top half into GB's, just to help out with filtration (yabbies are messy buggers in my experience)

or stock your system very lightly. ideally a 1:1 is the minimum you would aim for. im only just achieving it, and can only stock my small IBC system very lightly

alternitavley you could turn one IBC into a big biofilter with a huge pump (something in the region of 10000L / hour thru the IBC) which would aid greatly in the filtation of the FT. this would allow for a slightly lower FT:GB ratio.

nice system you have developing im going to follow it keely, partly because im going to build a bigger IBC system soon (not quite as big) and because i love re-using materials for AP

Well, you are starting big eh

Thanks guys,
to clarify, the 13200L would be total FTs (approx) - the other 6500L are round polymaster tanks, so if all top yabby beds were converted to GBs we would have about 5600L of yabby tanks left. these will overflow into our sump to cycle through system - We are thinking of using constant flow with these to keep the water a bit fresher instead of 15 mins every hour or whatever times we use for GBs. I reckon 10 yabbies per IBC would be max anyway once they get a bit bigger (if they last that long - yum!) Was also looking at minnows as feeder fish in the top tanks with the duckweed as we are looking at Murray Cod and Silvers or Jade Perch so would have a tasty treat for both if they will take it! Still thinking tho.

Sorry, I just realised that my calcs are slightly out as we were guessing at the total vol of the yabby set-ups being 750L tot but were looking at 300 & 350L = 650L but you get the idea

Have a spot available for this if we need it - have about 30 blue drums sitting idle as we didnt use them so could convert 1 to a bio filter if needed. I think we should be ok tho as we have the extra 16 tanks above the yabbies to convert once the load starts to catch up then we will go from there.

Mantis, I reckon we probably should have had a pilot for our pilot! but thats what happens when you have the space - ya just wanna fill it!

Wow, looks like a nice system in the makeing

For your info, I use 32mm pvc pipe for water supply to each IBC, and a 50mm drain. This works very well, and I have had no problems.

lol - your getting stuck into it

Like it, well done

Considering I hadnt slept much last night because I was up late resizing pics to post on the forum as well as hatching a duckling stuck in a sticky egg, I freely admit I probably now sound like I dont know what im doing, but wish to assure everyone I do have the correct figures on hand (although I wasnt using them when writing), and Im sincerely hoping at this point that I might be possibly smarter than I sound!

Thanks for the feedback guys!

thanks OBO, im so glad you posted that info as weve already bought the pipe and I have been worried that it wasnt going to be big enough - but looks like it will be fine.

Am using 40mm into GBs from FTs, then drainage is 25mm from GBs straight into 50mm then into 80mm before the sump (all pressure pipe because of 25mm tank outlet fittings). The yabby tanks are all 90mm overflow system using stormwater PVC - overkill but a cheap way of doing it because of the fittings we are using.