Backyard Aquaponics
A place to discuss aquaponics

for me, the smell of the tank should be the same as the smell of a nice clean creek, slightly earthy, but clean

Don't forget taste, it shouldn't be able to taste anything in the water either. Just leave the taste tests at lease 1 hour after the ammonia doses

Thats the reason my fish water taste like p--

Alright, while we're on the subject of water testing, I bought an EC truncheon meter today, as I thought it might be interesting to take some readings of systems with one.. Now I never hear of anyone using one in AP, yet in hydroponics, an EC and a pH meter are all thats used.

I know that they measure the electrical conductivity of your solution, so they will be measuring the level of dissolved salts (nutrients) basically. What I want to know is whether they will work for AP, has anyone ever heard of them being used in AP? Went back to Fayes house and tried it in here system that is growing very well ATM and it hardly had a reading.. Anyone have any idea why this might be?

prolly becasue nutes are being taken up as soon as they are produced, nitrates will prolly be very low.

Problem with an EC meter is that if you have salt in your system it will also register.

Sort of a side track but since we're comparing hydro and AP people need to remember that they are quite different in that a hydro system displaying low EC might stunt plant growth due to insufficient nutes and also inbalance of nutes where as fayes system might show great growth at the same low nute levels because they are constantly being produced and used.

in a hydro system you dose to a certain EC of nutes and then they run down as the plants take them up. Then you dump the water and re-dose.

With an AP system you might be putting out 40ppm of nitrates per day and the plants take up 40ppm per day. when measured the EC and nitrates may seem low but they are CONSTANTLY being produced and used in equilibrium.

Hydro applications typically utilise "small" reservior tanks.... from 20ltr to 200ltr.....

And mix nutrients to specific ppm or "concentrations"....... the concentration of the salts/nutrients (varying with pH) allows the electrical current flow that the EC meter reads....

In an AP system where the tank may be 2000-400ltr and an active uptake/cleansing of nutrients/salts through a recirculating flood and drain system..... I suspect that the salts are diluted beyond the capacity for the EC meter to read them... and indeed many of the "sulphate", nitrate etc etc salts are exactly those taken up within the growbeds by the plants...

A typical nft or DWC hydro system generally recycles the nutrient/salt supply around the system fairly quickly.....

Make any sense to people???

hehehehe, beat ya!

Yeah... just noticed

Steve and ange always ran VERY low nitrate ppms and were quite happy with the yield

The other factor/difference between hydro and AP systems in probably temperature ....

NFT channels/trays etc attract a lot of ambient temperature increase .... this leads to salt precipitation...leads to higher EC flow/reading.....

a factor magnified again by the lower volume reservior tanks and high concentration solutions

I'll be borrowing a meter that does EC this weekend, also DO, pH and probably a few other things too.

Hi joel with your truncheon it will only work if there is no salt in the water i have the meter version with no salt the max is 2 for fish safety .I put in 3 kg of salt the other day and it red 4.80 but i have found with the meter that salt disappears quickly

i went to a seminar this week for Myron L instruments they specialise in conductivity and PH meters probes, was verry interesting (and long) dont make a DO meter yet (i asked specificaly)

what readings did you get EB ??

the water in perth mains sits about 800 micro seimiens ( we tested it at the seminar) so id guess that in an ap system it would be a bit higher than that and if you have salt then much higher than that

i think ( but dont quote me) rain water should be about 100 - 200

Where is the best place to test the water. eg depth or near the inlet. Has anyone looked into where Am or Nitrite sit in a tank. Or are they evenly mixed.