Backyard Aquaponics
A place to discuss aquaponics

Hello, just pulled some tests and these are the results:

PH 8.1, amonia .25, nitrate 3 and nitrite 0....

now can anyone tell me what this means???? this system has been going since february this year; gave a decent crop of tomatoes; the new plants have not give a thing;; flowering but fall off; (mint and chives like it though) just planted new cherry tomatoes not seen in attached picks ; this is continous flow ; was thinking of putting an on off timer; say 15 min on and 15 min off..anyone know of a cheap timer that can do this around the clock?? want to see if this can "mimick" ebb and flow?? any thoughts; I am in south florida and it is very hot and humid; into the 80's and 90;s maybe this can have some bearings; the fish are tilapia; have about 100 in a 300 gallon liner tank created in the ground; and the water goes through styrofoam pots trickeling down into a collector bucket and back to the ground tank....lots of fun; but would like some advise from some of you experts out there;;;you know who you are..thanks.

Hi Art,
Welcome!!!! I'm glad you got onto the forum as I'm sure you will get tons of advice here. Just make sure to ask more questions when some one's answers make you even more confused than you might have been before you asked!

Bacteria usually like a pH between 7 and 8
Plants would rather have a pH between 6 and 7

In AP everything is a trade off and balance. My system is running a pH of 7.6 and gonna stay there because the media is full of shells. I have some trouble with iron deficiency because high pH locks up iron so I could spray the foliage with an iron supplement to deal with this problem. Other medias might tend to different pH like limestone may go closer to 8 depending on the variety. Peat or coco coir tend to have a low pH. Quarts river rock or granite I believe will be pH neutral. AP systems as they mature, will naturally have a tendency to drop in pH unless buffered by something like limestone, shells, other forms of calcium carbonate or other things that raise pH. The pH generally needs to be kept above 6.5 or certain bacteria will stop functioning.

Anyway, I believe you mentioned that you media has limestone in it and that is probably a big part of the reason you pH is at 8.1.

On to the other test results. Fish excrete Ammonia which is converted by bacteria into Nitrite and then different bacteria convert it into Nitrate which the plants use.
Ammonia
You would like to keep this as close to 0 as possible in a system that is "cycled" The higher the temps and the higher the pH, the more dangerous ammonia is. .25 isn't enough to cause a panic, but it would be nice to sort out why it is more than just a trace.

Nitrite
You want the Nitrite to be 0 in a system that is "cycled". Since you have 0 Nitrite, that is good.

Nitrate
This is what the plants use so you do want some of it. The exact amount you should have in a system doesn't have an exact answer. I think most people run between 5 and 100 depending on how many plants they have in the system to use up the nutrients. I think mine are at around 80 right now so I'm planting more stuff to use it up.

Again welcome!

Thanks TCL..

Art, thats a very interesting system, I like the look of it

As a renter I'm always on the look out for systems that would not take too much to move

thanks gnash..

G'day Art and welcome to the forum, as TC said pH is slightly high to what we like, the preferred range being 7-7.4 - having said that, mine is below 6.6 and I am having problems raising it

There is always going to be ammonia in the water, especially if you take a test after feeding where it can rise up to 0.25...over this and it becomes a concern.

Flowers not setting and dropping off could relate to deficiencies - fish pellets don't cover all the minerals etc required for plant growth...some of us use seasol as a foliar spray, chelated iron, different types of crushed mineral rock and potassium can be added by burying the odd banana in a GB.

Stay away from normal fertilizers as they may contain nasties to the fish...to give you an idea, this is the mineral rock supplement that I use

MinPlus

Damn, I knew I was good..........now I have been immortalised

it happens with age

Be wary of the minplus, it will raise your PH, also, use a timer for your pump. You will want to try 15 mins on, 1 hour off.
I think your plants may be too wet if they are getting that amount of water 24 hours.

I tend to agree with Outbackozzie about the wetness of your plants etc...
I ran most of my system on continuous flow since I started AP... I have done a little experimenting (not as much as others here) and have found that having a break from the flow of water... Some plants do well enough but most do better if you have a good break. In fact I am moving from continious flow (where ALL my beds are fitted with auto siphons) to flood and drain, with at least a 30 min to 45 min break between floodings.)

The good thing about my big system, all the beds flood at the start of the day, then drain, and the syphon keeps the bed drained for the rest of the day Its a good accidental 'feature'.