Backyard Aquaponics
A place to discuss aquaponics

Where do they hide? Do you have a spot for them? We have crayfish here and I have been entertaining the idea for the kids. I've heard they can be cannabalsitic. I imagine this is simply a territorial issue? Also have you ever bred them?

Cool Simmo, your systems are never boring!

Are you concerned with evaporation with the water squirting up in the air like that?

MF - I've got small sections of PVC piping in there with them to hide in, now that the water has cleared up I might see if I can get a pic for you. They can be cannibalistic, some species more so than others, but I think if you provide lots of hides for them you can stock them at a slightly higher rate. While my Marron are small the tank is fine for them, I will have to watch and see how they go when they get bigger. If there is a drop in population due to cannabilism I can always get rid of the goldies and move the larger ones to the other tank.

DD - Thanks mate... Its funny you should mention it, I was looking at that same problem just this morning (but from a slightly different perspective). The wind was blowing some of the water out of the growbeds, and I think you are right that it will be causing excess evaporation so I will redesign the sprinklers today I think. Watch this space...

Rupe - I'm not the sort of person who will remember to take temp readings on a daily basis etc , but every now and then (when I remember) I will dip my hand in both the tank water, and the return water and see if there is a noticable temperature difference. I expect that the black tubs would heat the water to some degree.

Irrigation mod...



MF - I did (unintentionally) breed this batch of baby Marron - check out my system II thread. Crays are great fun, my mates kid is fascinated by mine. He keeps asking to come over and see the 'crabs'.

hey simmo,

nice neat looking system.

i would be careful with the the water coming into the growbed like that. i did similar and had a problem with stem rot. the water was splashing off the rocks and onto the stems of my plants. i redirected the flow downwards and placed the pipes on the gravel. i found the plants responded well to the change.

always good to have a "holiday" to work on the system. hope the weather stays cool for you.

keep it up mate.

Cheers BF - I reckon the mods I've made will fix that, theres very little splashing now - the rocks were still wet from the previous setup when this pic was taken. It was 3 days of solid work to dismantle the old one and set this one up, but the holiday has started in earnest now

The system has been cycling for 3 weeks now and I have some serious pea soupage happening

Last weekend I started to notice the first signs of algal growth on the inside of the IBCs, for the first two weeks the water had been crystal clear and I was able to see my marron foraging around on the bottom of their tank. This weekend I can only see the goldfish if they come within around 20cm of the surface. It's amazing how quickly it has changed...

The "pea soup" stage is perfectly normal of course. I figured I was probably another week or so away from being able to sow some seeds in my growbeds, but I decided to dust off the test kit to see exactly what was happening as far as the water chemistry was concerned.

First I tested the pH and was a little concerned that it was up to 8.3

Ammonia was next but the test showed close to 0 ppm, I tested again to be sure and got the same result.

The Nitrite test gave me a result of 1 ppm and as such I didn't bother doing the Nitrate test.

A question for the experts here - do I need to worry about my pH or Nitrite test results? I can't see the marron but my goldies are fine and are still eating (but they are a fairly hardy fish). Should I do a small water change or attempt to adjust the pH or should I just leave the system to cycle?

Thanks in advance.

Hi Simmo,
It sounds like good progress. Do a 50% water change if you can. Cut back on food. I do 50% water changes daily if nitrates or ammonia are 1 or above. You are half way through cycling.

The pH will naturally come down a little when you do the water change (assuming your source water is below 8.3), and will come down further as the system establishes. It would be nice if it were a little lower, but I'm in the camp that hates to mess with pH.

you mean nitrites yeah Janet?

I think Janet is right, although 1 is not too high. when I was cycling my silvers tank nitrites got up to 5 or 6 or maybe more, I know KE14 got his over 10 without any casualties. Just cut back the feed a bit, small changes and off ya go. Maybe cut the light levels a bit will help with the pea soup too.

Cheers guys, we've had a fair bit of rain here today (about 5mm) and theres more on the way, so I've managed to catch some water I can use for some small water changeouts. I'll only do 100L or so at a time over the next 2-3 days and check again midweek.

Yup, I mean Nitrites, not Nitrates. I'm pretty conservative on letting nitrites/ammonia get too high.

Simmo, how about an update? (saw your name as being online right now)

Hi Dave, it just so happens that I've been taking some pics and I'm in the process of uploading them to my ISP as I write this - stay tuned for an update in the next hour or so...

My apologies to everyone for being away for so long. I've had a few problems with my system over winter and and been very busy in my non-AP life - so I've been neglecting the forum for quite some time now... (only 13,000 odd new posts to get through ).

I got re-inspired by seeing Faye's fantastic AP setup & garden before Xmas so I decided to get the problems ironed out and get my system running properly and reliably again. You'll see from the pics I'm about to post that things are really going well, you could say I've been bitten by the AP bug again...

Anyhow... details to follow shortly.