Backyard Aquaponics
A place to discuss aquaponics

I picked up 11 large SP the other day, now to convince them to eat my offerings.

Give them some time without food, they'll come around.

thats what im doing, they have been in for about 4 days, threw in a tiny amount last night left it for 5 mins then scooped it out, they where looking very inquisative this morning though swimming around the top of the tank instead of just hiding in the bottom corner (hopeing thats a good sign)

The Affnan siphon modifications seem to be a good way to go to get good steady operation with a siphon if a plain and simple straight siphon doesn't work right away. Messing about with traps and breather tubes often just gets cumbersome.
In general if a siphon starts fine but doesn't cut off, then the bed is running constant flow but always drained so small plants might have a problem getting water but the usual cause of this conditions is either the flow into the bed is too fast, the gravel guard is too restrictive or the siphon can't get a good gulp of air (as it there isn't an air gap near enough the bottom of the drain of the grow bed for the siphon to break.)
If the siphon doesn't start but water just trickles down the top of the stand pipe but never causes the bed to drain, the problem is usually not enough flow into the bed. Usually the best way to handle this is increase the flow into the bed a little bit or switch to an affnan siphon. Sometimes putting a little restriction at the bottom of the drain can help but be careful since restricting the drain too much might also make it hard for the siphon to stop when it comes time. If the water inflow to the bed is too slow to trigger the siphon then you wind up with the bed running constant flood but overflow is unlikely under this condition since if the flow to the bed speeds up the siphon would trigger.

However, if the siphon isn't triggering properly because you have some media that got into the drain, there could be an overflow problem.

I am finding all these things out about siphons and have all 4 beds working 2 with affnan's now and 2 with bells, the bells have breather lines that don't work because they are too small, and also about every second day i will find them failing to stop, but am having fun playing with siphons and outlet restriction, I think by the end of the weekend i will have 4 affnan's though.

have just found another problem and rectified for now by cleaning, the pope irrigation valves I am using to control the flow rates into the GB's have screens across the inlet/outlet and there is string algae getting in and causing blockages, might have to try and drill out the grills or find valves that fit that don't have grills.

Yea been there made that mistake. You can use a drill to bore out the centre like you have mentioned.

the real sad thing is I didn't think about it till I had put it back together, oh well to pull them all apart again.

Ok I need help here,

Came home to find 3 SP stiff and belly up on the bottom of the tank. Did water tests on their tank instead of the sump and have

PH 8
Amm 0.25ppm
Nitrite 0
Nitrate 40-80

Removed the three dead SP removed all the Valves cleaned and removed the grates that where becoming blocked, checked the pump and all is back together and running again.

Could it be possible that DO is my problem? the total volume of water is turned over twice an hour and drops from the GB to FT then again to ST, I also have a small 360L/H air pump split in two one in the Koi tank and 1one in the SP tank.

Nothing i could see wrong with the three dead fish at all.

Any and all help appreciated don't want to loose all fish again

Is there a link to your system with some pics? Not really enough to go on here to answer your question. Any idea what time of day these died? What's your water temp? Is there lots of algae growing in your system? My first inclination is just to chalk it up to stress since you haven't had them long.

So just the three died and the others were fine? Keep a close eye on them.
And yeah if we can have some pictures of your IBC system that'd be helpful

got a better look at the other eight after dark and a couple have visible damage to their slime coat, not sure what the temp of the tank was but will be able to check tomorrow afternoon (fingers crossed), forgot to mention that the salt is at 1-2 ppt, there is string algae in the two tanks that have fish in them but i remove it most afternoons and its not even a handful, I also put my small 3000L pump back in the sump and have it going straight to the SP tank to turn over more water.

I have a better idea of what is going on now, I thought that ICH presented deferently, but after some googling and reading some threads on it I am convinced that my fish have it, covered in tiny white flecks and the slime coat turning an opaque colur, also the same as the Barra that i lost last month, so I put in another 4kg of salt last night, will do the same again tonight and see how i go.

Yep, Ich will do them in. Glad you figured it out Brad. Hope you get it under control quickly

Next little thing, should I try and remove the Koi before they start to get it or is it already going to be on them in the early stage?