Backyard Aquaponics
A place to discuss aquaponics

Love those Beetroots too. It looks like our media beds are already clogged as well. Ours are only one season.
I'm now leaning toward DWCs.
Do you have worms in your beds?
Looks like you made the right choice going with rainbow trout.

I have worms, Boss. My challenge is the large volume of fish waste being processed by too few growbeds and pre-growbed filters.

I'll be in that boat as well with 100 Brook Trout in a system with around 5m3 media beds if I did that correctly. I also have a MBBR of .2m3 Fish are growing fast and I will add more MBBR.

A week or so ago I caught a small brown trout (Salmo trutta), one of a dozen or so that have been swimming with my rainbows.
It was small but there is nothing to be gained by throwing it back at this stage of the season so I cleaned, cooked and ate it.
My verdict - sensational!

My verdict - sensational![/quote]

That's what I was wanting to hear, they are a bit slower growing than the Rainbow but I might try a few in my next batch.

Thanks PLJ

I was re-reading some comments made over the last few weeks and this one caught my attention because I believe it to be false.

My tank is outside and thus tank water temperatures and seasonal ambient temperatures will eventually equalise, but this doesn't happen each day or in a few days but seasonally. The way I see it, an adequate insulator of any description will retard the change in temperature of the body of water in either direction on a seasonal basis. This means that as the daily temps increase in spring and summer, or decrease in autumn and winter, the tank water temperature will follow but at a retarded rate. The better the quality of the insulator, and the more complete the insulation, the more effective will be this temperature retardation.

The same applies to piling soil up against the walls; it would work to the extent that it would retard the rise in temp of the water and thus extend the trout season, and that is all I'm hoping to do. I have no plans of taking trout through the summer until the next cool season, but having a thermal buffer that would allow me to keep and harvest the trout over a longer period would be valuable.

I have about 90 trout left in my tank. The temperature of their water is such that they haven't actively fed for three weeks but remain in a holding pattern until temps either rise or fall. Of course, the temperature is gradually rising so I need to get them out before they go 'fins up'. Catching them is problematic when they aren't feeding so I'll have to bite the bullet this week and drain the tank of about 75,000L of my precious water. I reckon the waste of the water is less costly than is the waste of good fish.

PLJ - that's the question:

How long is the delay? Of course it will slow down heat transfer, but it all works towards equilibrium.
Daily temperature swings, sunny vs. rainy weather, seasons....

If the system can "get rid" of heat aquired during the day - your temps will stay put.

But that usually that doesn't happen, that's why those with temp-sensitive fish - usually - are in trouble...

The idea about isolating the tank/water transfer/grow areas is to slow down temp transfer enough, so the materials around can radiate their heat energy aquired during the day back into the atmosphere/space during the night.

With isolating you only try to keep the whole heat cycle away from the water...
And of course it is not just the tank, but everything your water circulates in....

The main effort is avoiding the sun hitting any part that conducts water and the water itself.
Of course this becomes a little "interesting" around the plant areas - as these need sun light.....

Cheers,
thjakits

I've seen people put styrofoam insulation over the media in beds. I'm not sure how much it would help, but I would think white styrofoam wouldn't attract the sun and warm up as much as brown clay balls for example.

I'm considering if it is worth the effort to insulate my beds in my greenhouse against heat loss, but I might lose heat by not having the sun hitting the media during the day so I'm undecided.

HEY PLJ,

Rather than choose between the fish or the water, why not invest in a small speargun, snorkel and flippers?
You could then choose which fish you want to harvest, when you want to harvest them and keep the water.

With 75000 litres, it would be like shooting fish in a barrel......oh wait!

Nhibbo, the water is brown from tannins so visibility is very poor. Even with an underwater torch the speargun option, or any equivalent sight-based method, is a fail, unless the tank depth is reduced . See this page.

After draining 75,000L of water from my tank I will be left with 15,000L, which will cover the bottom to a depth of about 330mm. Only at this point will I be able to choose which fish I want to harvest and have a reasonable chance of catching it. In fact, I plan to scoop all of the fish out at this point but it still won't be particularly easy. A night-time operation with suitable illumination may well provide me with my best shot at scooping them without causing a lot of stress - for the fish and me both!

Any ideas/plans on a screening net set-up??

I think some frame-work with PVC and nets could do the trick...

thjakits

I wish I had those size fish, your pumping them out

+1 I would think with that size of tank you would want some kind of cast nets or something like that rather than just hand nets. Some of the nets you can set up across the entire tank and have it sized so smaller fish can swim through it but bigger fish can't, then just grab one side and drag it around the tank and pull them out. That's how I would expect commercial aquaculture to do it, and on your scale you are as close to commercial aquaculture as I've seen in someones backyard.

Hello mate.

I hope you don't mind me wading in but I have an idea how you can keep the water temp down while giving you much more veg/fruit grow space.

If you went with vertical grow towers, white ones to reflect max amounts of heat, then covered the plastic with a reflective plastic, you could grow plants of your choice up the wall of your tank.

I built a set myself and they are doing fantastic well and are very low maintainence. Make sure you pump clean water (post filters to towers to avoid blockages) I also have a fine mesh filter that I clean every 2 weeks. That stops all blockages in towers.

I also did Dutch buckets on a platform. If you were to set up a walkway on the rim of your tank you could have a row of fruit trees on the rim. These would shade the water and you wouldn't need much pump power to have 1 Dutch bucket every meter.

These 2 ideas together could keep your water temp pretty low for longer.

Lastly, you might be better off with a barrel swirl filter and 2 IBC tanks for your bio filters. That would allow you to stock pretty heavily. You might also try finding a 3 compartment Koi filter. Second hand ones are cheap and they are very easy to run. They clean water very well and are easy to clean. You then run from koi filter through IBC moving bed bio filter.

Just my thoughts.

Lastly, if you need uniseals, I'd be happy to ship to you at my cost. I don't sell them,I just buy them in from the states in bulk for personal projects.

I wish I had the space you have! Lucky lucky man![EXTRATERRESTRIAL ALIEN][EXTRATERRESTRIAL ALIEN][EXTRATERRESTRIAL ALIEN]

Sent from my SM-N910F using Tapatalk

So, after some thought and a rough drawing, here is what I would do with your tank. It's a fairly big job but it could be amazing!

In this tank the water level is constant and you have an open T at the top to prevent the pipe from creating a syphon and suckling your tank dry.

The large pipe allows you to use the full potency all of your pump or your filters. As water pumps in the top it creates a swirl pulling the waste to the middle of the tank. The sloped floor helps this.

The floor drain has a mesh cover so only solid waste is pulled through. The fish are unable to fall through.

The waste then flows to the filters which would be your main flow limiting factor.
So you can make the biggest, most efficient filter system you want and turnover 70 000 L every hour.

At the bottom of the outlet I included a drain to allow you to drain the tank or deal with any blockages or settled muck.

I know it's a big job but you won't regret it for a moment once it's done.

I'd love to hear your thoughts on my idea. It will decrease the tank volume bur you already said you plan to keep it at around 50 000L.

As you add water to the tank the water overflows through the solids lifting outlet pipe so you can't be drained completely.

For safety I recommend locking the drain valve with a padlock to stop kids from fiddling.

Sent from my SM-N910F using Tapatalk