Backyard Aquaponics
A place to discuss aquaponics

Not that long Nenexus… certainly not as long as Joel, Rupe and many others. I dabbled with AP a couple of times many years ago (the first time I didn't know what I was doing even had a name), but didn't throw myself into it until about three years ago. Being a horticulturalist, the plants and their pests are more my forte, although I have been keeping fish, yabbies etc for about 8 years now, I only really started to try and learn the intricacies of fish keeping in the last year or so... out of necessity.

Rupe is the go-to-guy for fish health problems. I replied to your thread because I watched it for hours and nobody was replying… and I’d seen similar scenarios quite a bit lately... but Rupe's onto it now!

I think Rupe mis-interpreted that one... 1ppt is considered acceptable to maintain in the system for general fish health, in all honesty, your plants may well do better with 1ppt of salt in the system. The plants will use the salt so you will need to add more salt occasionally to maintain 1ppt. A salinity rectometer will help you maintain the salt level accurately, they are about $40-$50, Rupe will be able to tell you which one you need.

You can certainly maintain 1ppt in your system constantly... but it's not a necessity...

The Salinty refractometer to use is an ATC Salinity Refractometer....

What about the increments in the meter?... there’s a couple of types and I remember you saying that one isn’t worth a pinch of goat poop.

And everyone is fully aware you prefer timed F&D over siphons, so any discussion is going to be subjective... on both our behalves.

One would assume the overwhelming majority of people setting up a sipnoned system would install a spray bar set-up, to by-pass the extra flow/pressure from their pump, back to the FT, when tuning the in-flow required into the GB to get the siphon working… Whenever I remember, I certainly add the “oversize your pump and install a spray bar in your FT” disclaimer when advocating the siphon system...

...so with the pump running 24/7 in a siphoned system there is aeration and water circulation in the FT 24/7… plus the rush of oxygenated water at the back-end of each F&D cycle.

Nonsense!… Says you!

Also, it could be classified as a “trickle” at best... how much oxygenating is it doing?

I’ve never said anything of the sort!... but I do recall you posting on a few occasions that there was no discernable difference between the systems in the wash up.

“Littered”...

Those having trouble with siphons haven’t constructed them properly, or tuned them properly. It may be frustrating if you try and make your own from scratch without seeking advice first, like I did the first time, but they are very simple and very reliable if you ask questions of the forum, or use the search function, prior to constructing one.

I have sold dozens of pre-fabbed siphons kits and have never had one customer call me up and say they couldn’t get it working… not one!... because I explain the tuning process to them... it’s not exactly rocket science. Alternatively I have a box of about a dozen timers, of a number of different brands, in my office that have been returned in the last couple of years.

Can't remember that particular discussion... but normally they have a 0-100 scale...



Some people say this is too hard to read... and there are models around with a 0-10 scale.. but I'm not sure if they were "salinity" refractometers... or Brix meters... (might be the convo you're referring to??)

Recently there's "new" ATC refractomers available with a 0-28 scale... for instance... (no endorsement meant)






Very true... in terms of personal preference...

My post wasn't directed towards personal preference... just your analysis...


But this stands just as true.. in the same circumstances.. with a timed F&D configuration... other than the spray bar obviously would only provide the additional aeration during the timer period...

But that wasn't the point being discussed... in terms of comparison between siphons.. or timed F&D...



Well yes... initially it's only a "trickle" when the pump first begins... but very soon after it's probably at least a 25%+ flow.... and within 5 mins is a full flow...

The point was that you recognised the "trickle" flow once the pump was off... in terms of your premise.. but not when the timed period began...

The main point though.. was you "postulation" of "still water"... and a (faulty) comparison.. and conclusion that a siphoned system either negated the problem, or was more beneficial..

When in fact... they were the same...


Oh, agreed... siphons aren't particularly difficult... or shouldn't be....

But many new members... regularly post that they're having problems with them...

I haven't seen very many posting.. that their overflow standpipe isn't working properly....

Other than perhaps a few... that are over-wealming them.. and flooding too high... for the same sort of flow reasons..


And yes... I did see one batch of timers... the first ones made in China for that particular brand.... that were bad....

But it didn't take long to find a reliable replacement... and I'm still running one that I've used since day dot....

The only timer failures I've really seen... are the result in people winding the timer around against the preset pins...

Disengage the pin cam if you need to adjust the timer at all.... (manual over ride)

I think this depends on the pump. I have a couple of low volume cheap pumps in the greenhouse system and the same thing would happen with them. They sometimes would not start and needed a jiggle, bump whatever to get them to go. I wanted to run a couple of beds in there on timed flood and drain so put in a pump I got originally from Murray and it starts and stops no problems. Also I have the pond system on timed f&d with a luguna pump and its been running 30:30 for months with no issues

I would think that a pump that had to be jiggled in the water was a sign of a failing capacitor not bioslime.
If it is a failing cap your pump will not be working efficiently.

Nope... but it's only a 950Lph pond pump with resin sealed componenets, so there's no chance of replacing anything.

I just take the impellor out and use a tooth brush to remove the bio-film that's built up around the inner surfaces of the hole where the impellor normally sits, and I give the impellor a bit of a scrub... stick it all back together and it goes for another few months.

I'd replace the pump and use the old one as emergency backup.

Rupertof0Z...Ok thanks for that.

I'm just wondering, if I'm to add new fish in 2 weeks time (post 1wk of Potasium Permangenate & 1wk of salt treatment) how do I keep the bacteria alive and healthy until then ?

BTW I have also heard more stories off line about a particular major fish supplier in Perth. The same fish deaths occured with them also, so I was not alone with my bad experience. Interesting...

If you have no fish Nenexus... you could add a level tablespoon of urea.... once a month.... to boost your ammonia... and bacteria...

But if you've only two weeks to wait for fish... I wouldn't bother... the bacteria wont die off much... and will kick back as soon as fish are in the system...