Backyard Aquaponics
A place to discuss aquaponics

HI All,

Am after some sage advice if you would oblige. Picked up 10 Trout, about 12cms long each from Tooperang, also bought a small amount of pellets (4mm I think).

How much should I feed them at a time?
How often should I feed them?

Thanks,

dustintheshelves.

That all depends on a few things really.. Has your system been going for at least a couple of months? And fo you have a good amount of growbeds to match your fish stocking? If so, you can feed then a couple of times a day, as much as they will eat..

Just throw in a few pellets, wait till they eat it, then throw in a few more. Repeat till they slow down and aren't obviously ravenous.

Thanks earthbound!

My current system parameters are:

750L tank with 10 trout at approx 12 cms long

600L growbeds (2 x 300L)

GB stocked with small lettuces, broccoli, snow peas and spring onion, probably not much bigger than when I bought them, though they are starting to go.

System cycled from mid april to last weekend (so about 8 weeks) without fish and no plants.

I practiced pee-ponics to kick the system off after about 6 weeks.

The 10 trout are fed 20gms of barra feed daily and it appears to all go. This is based upon a feed rate of 8% of body weight, which I calculated from MrOrange's weight/length analysis I found on the forum. Small though the sampling is, it's probably reasonable as a guide. I intend to reduce the feed/weight ratio to 3% as the fish get bigger.

Water tests:
12/06/2011 22:55
Temp 10
pH 8.2
Ammonia .50 ppm
Nitrites 1.0 ppm
Nitrates approx 3.0 ppm

18/06/2011
Added 10 trout from Tooperang. Estimated size 4-5 inches. They appear happy.
Temp: 11

19/06/2011
Temp: 10
pH: 8.0
Ammonia: .25
Nitrites: 5.0 ppm
Nitrates: 5.0 ppm

20/06/2011 8:00am
Fed 20gms pellets

21/06/2011
Fed 20gms pellets

22/06/2011 9:40 am
Temp 10
pH 7.4 high range
Ammonia .25 ppm
Nitrites .25 ppm
Nitrates 10 ppm
Fed 20gms of pellets

For my mind it's probably a bit early to say, but the numbers look reasonable. Ammonia is not too high and the initial ammonia / nitrite spike seems to have worked through. The fish seem relatively happy, not listing on the surface or crowding around the air stones, and they seem to eat all their food.

A 1 min video of my system:




Thanks for your time EB.

dustintheshelves.

600L of GB should be able to support 10 - 15KG of fish when they are at their peak.
feed as much as they like, keeping and eye on the ph, it will most likely fall as the process kicks in.

Regards
Matt

Hi Matt,

Thanks for replying! I've decided to feed as much as they eat, twice a day (ish). I am testing the water every second day and all seems good at the moment. pH has done stuff all for a couple of weeks, hanging on to 8.0. After initially trying to lower the pH before fish (unsuccessfully) I have decided just to be patient. Fish are happy and the plants, while growing very slooowly (it's cold here), are looking fine.

Ok 10-15KG's of fish, how would that many fish go in 750L of water, which varies as it's not yet a CHIFT PIST system? I have 2 bigish air stones bubbling away 24/7.

I only have 10 trout at the moment, as I didn't want to overdo a new system.

Thanks,

Dustin