Backyard Aquaponics
A place to discuss aquaponics

Although I haven't weighed them, I wouldn't anticipate that they are 300g! I would assume up to 100g

Marcus, I've got the same amount of SP as you (same size too), just weighed my "feed scoop" at 15gms, the fish get 2 spoons/day so that's about what you estimate (also toss in duckweed and lettuce leaves etc).

My fish are doing fine, the veggies are doing fine, Les is doing fine

I had my first casualty yesterday in my six months of Aquaponics – one of the gold fish. He seemed very much the worse for wear, fins were all split and his tail seemed to have bloody veins at the base. He had been chased constantly by the other goldfish and the perch had been worrying him of late once he became sick (which happened virtually overnight).

The other 3 goldfish also seem to have ragged tails so they have been removed from the Perch tank and are in the 120 L yabby tank which I was setting up – no yabbies yet – so it is well planted, has plenty of hidey holes and duckweed! They seem a bit in shock after being caught as they are “resting” on the bottom of the tank. Their fins didn’t seem the best either. I added two table spoons of salt so hopefully they will pick up over the weekend.

Other than that the perch seem fine, they are growing and after a feed they get very territorial nipping each other for about 40 mins then afterwards they settle back down and shoal.

Last weekend I added 2 table spoons of sodium bicarbonate (to about 1000L), which took the PH from 6.2/3 up to 6.6ph immediately. It is now back down to 6.3, and ammonia 0.1. Grow bed is still running constantly and the spider mites on the grow bed are going wild. Plan to re-crop with silver beet, lettuce and basil – the mites seem to like tomatoes and peppers, but not the former.

That's my latest news!!

Marcus,
I use crushed shells and coral to keep my pH right at 7.2, steady as a rock as long as the bio-load doesn't have a sudden increase. My system is only a few months old, but the coral/shells are working well.

Marcus two things to try for your Spider Mites...(Posted in Red Spider Mite thread)

Spray with "Maxicrop" Liquid Seaweed....

Spray (notes say at sundown) with a mixture of 10 parts water : 1 part "expresso" coffee... needs to be strong... expresso not instant

Marcus, I experienced the same problem when mixing goldies and SP, the SP gang up on the goldies, herd them to the surface and then attack from underneath - mine had scales missing and sides ripped open, separated them and the goldies have recovered (well 4 of the 10 have).

I put it down to the size difference (most of SP were larger than the comets) but it may also be sheer numbers.

Interesting to note tho that other members have not had this problem

my two goldies also died unexpectedly............might be a thing with the perch once they get to a certain age. Spewing too, the shubunkins sp? had gotten really big.

My goldies (commets) live in harmony with the silver perch and jade perch - which vary in size the biggest being about 25cm and 300 grams I would suspect. I bought all my goldies as feeder fish and used them way way ago to cycle my original system. I was lost several over time for various reasons (like getting stuck in pumps). Most of them have turned into nice gold commets. Interestingly the gold ones spend all their time very close to the surface - but the 1 or 2 that stayed black live at greater depth. I figure that the darker ones think they are perch and have been accepted by the school. Now and again the silvers do give the goldies a nudge - so they have the odd missing scale - but I think this is normally by mistake because they could easilly kill and eat them if they wished.