Backyard Aquaponics
A place to discuss aquaponics

I grow pumpkins in the soil and have done pretty well with them. I got approx 60 japs from my 1 plant last year. The thing to know about pumpkins is that although they often produce female flowers early in the season, for some reason they often don't polinate - even if done by hand. Then later in the season you get heaps of pumpkins setting. Moral is - don't expect too much too early, it may come a bit later.

Do you know for how long your nitrate has been zero f&f. How many fish do you have again and how big are they?

Sorry mate, busy yesty - before answering doing a bit of back of the envelope calculations

travel @ 2-3k/h
distance Melbourne - Brisbane (2,000km)
factor in sleep, meal and refill breaks..............
about 2 months before F&F bulldozes my house down


Geeezzz you've done excellent there F&F, might I suggest a slightly more patient approach when using the fundamental AP tool apparatus, but otherwise top marks

all the zero nitrate mean is that the plants are sucking every last bit of nute out of the system as they are made. Obviously his plants tell a happy story

The only catch with the nitrates is that at some point previously there may have been a nitrate reading, but now the uptake by plants has become greater than the input from food (fish) .

If the plants are ready to start harvesting in bunches then i'd leave well enough alone. Actually if you can get it this balanced then its really good, as some people are concerned with residual nitrates in the plants.

As the plants are harvested and seadling replace them the nitrates will come back up, all other things remaining equal.

Steve - my thoughts are a little different to yours, but not much. What I figure is taht if the nitrate is 0 because the plants are stripping every little bit, then these means that what is being produced is less than what the plants need. The ideal balanced system would be where the nitrate remains stable at the level you are after, say 80, so that you know the fish and plants are operating in sync.

I do agree though that if the plants are doing well, then what more can you ask for. I'd just be watching for any indication that they are now longer doing as well as they were. Then doing a bit of a harvest would be the thing to do - to bring the nitrate production and use back in balance.

Hi 70 silver perch about7_8 in long nitrates been 0 3 or 4 weeks

It's always going to be a fine balance. All I would say is something common sense which I'm sure is not providing you with any info you don't already have F&F: Maintain the plants at current stocking level until the nitrate starts to register. The fish will produce more nutes as they are fed more because of their growth and no doubt some of the plants will also use more nutes as they grow bigger and/or fruit.

One other thing you could consider is increasing your feeding frequency. How often are you feeding and do you feed until they stop rising for the food?

I agree:
with Steve - if the plants are doing well at 0 then it is balanced
with vb - if nitrates are at ~80 and remains stable then there is a buffer before HSM

two bob each way

Hi as for feeding its a bit lax at the moment feeding about one hand full night and morning!

This is the easy solution then F&F. I would increase feeding rate significantly and watch for nitrate increase. Once the nitrate gets to 40 or 80 then you can regulate your feeding to keep it there. Under this method, you will feed more when your plants are using more and less when they need less. Do I need to explain better?

will go for it then [stil feed twice a day or 3 times better]

vb's signed off - I would stay on twice a day so that their routine isn't disrupted too much

Yep - I'd just try feeding them more on those 2 sittings F&F. From the description you have given, I am sure they will eat more.

My fish seem to either be interested in food or not, so I would say go for when they are to it, feed as much as they will eat for a while and monitor your levels. Your plants look magnificent, obviously loving your sunny position too, lettuces look lush well done!

VB i think your on the mark i feed every 2 days with 200 grams of caned prawns cheaper than fish food when on special. redies wont eat fish food anyway, nitates go up to about 40 pants start to look better and fish dont seem to be hungry for another 2 days nitrates drop to nealy zero so time to feed again 200 grams seems to be enough they go mad for a start and slow right down when the food is nealy all gone i hope this is the right way to go i have spent lots of houres looking into the fish tanks checking and trying to learn there feeding habits.
jim.