Backyard Aquaponics
A place to discuss aquaponics

Hi,
I would like to know what the ideal PH (amonia), NO2 (nitrite) & NO3 (Nitrate) levels should be. Following are my readings.

PH = 7.5
NO2 = 0
NO3 = 200
KH = 40
GH = 180

I have been struggling with aquaponics systems for over year and half now, I have not lost any fish in those years. But for some reason, most plants don't survive in my system. Ones that do survive grow at very slow pace. I had few tomato plants in my system it took them almost 1year to flower but then for some reason plant died.

Please help me get my system going properly.

I have a 30 gal tank, with 15 feeder fish, they are about 1-2.5" in length.

A pH anywhere between 6.0 and 8.0 is fine, with high 6's, about 6.8, being a happy medium that keeps plants, fish and bacteria happy.

N02 should always be 0.0

N03 between 0.0 and 40.0ppm is fine. If it sits above 40.0ppm on a constant basis then you need more plants, or plants that better utilise N03.

200ppm of N03 is too high, seedlings of most plants won't like it, and it will inhibit flowering/fruiting plants from flowering or setting fruit.

I would greatly reduce the feeding for a while, reduce the amount fed each time, reduce the number of feeds per day, even miss a few days. Then do a few partial water changes (ie: 20%) with chlorine free water (aged etc). Once you've got the N03 down by at least half, plant as many fast growing leafy greens as possible, even if you over crowd the GB. Once they've established remove any fruiting plants and replace them with even more leafy greens.

Also, make sure you are feeding your fish a good quality, commercial grade feed.

When the N03 is under control I would start adding a seaweed extract (Maxicrop etc) very sparingly, ie: a capful per 500L, per fortnight. This will provide trace elements. Don't over do it with the Maxicrop, it contains far more Nitrogen than the Seasol version we use here in Oz.

Not to disagree with mr.dammage, but my nitrates are always rather high, and I have tomatoes and eggplants fruiting like gangbusters, even in January. I also use maxcrop. Though I just started.it made the difference between my plants in the indoor system barely surviving, and blasting off. I do not use it sparingly, I bought the powdered stuff, and add a teaspoon of it every week or two.

Hi Ron,

I'm just starting up and hope to add fish soon. I have an IBC simple fill / drain system for now with about 150 gal's of lava rock grow bed media and 175 gal of rainwater in the bottom IBC container. I was cycling for a couple weeks empty, then a few couple more with a few goldfish but they were stressed (I was losing one or two a week). So I took them out and started adding ammonia (pure) about 5 days ago. I see a lot of talk about Maxcrop and I have some Maxcrop plus iron I want to add. But I don't see any info on how much to add for starters. My current numbers are:

pH 8.0
Ammonia 4.0
Nitrite 0.5
Nitrate 60
GH 60
KH 80

The pH has been 7.5 for weeks until today. I was hoping it will come down not go up. I only have a few transplants so far in the beds: 9 lettuce, 3 basil, 3 brussels sprouts and a few onions and 3 strawberries I threw in 'cause I had them.

I would like to get a little iron and trace minerals in the water now so I am not making any large changes once I add fish. I plan to start with about 20 catfish fingerlings.

Thanks in advance for any advice.

PS: I believe you are in Chula Vista. I'm in Santee.

Yup, Chula. I wish I could give you hard numbers. I add about a teaspoon of the powdered stuff to my indoor system. The water gets quite dark, then clears up in about half a day. In my outdoor system, I add a heaping tablespoon. I add it by filling a pitcher with a water, and mixing it up in that, then I pour it in my system wherever convienient. In my indoor systen, that is right in the fish tank. In my outdoor system, I usually pour it into the grow beds at the base of the plants.

I'm not sure where I got this but somewhere here on BYAP and this is for the liquid version of maxicrop -

Maxicrop - Between .25 and .5 Oz per each 10 gallons for first dose then 1 Oz per 200 gallons every two weeks. Reduce or stop additions if deficiency symptoms go away.
For foliar feeding 1 Oz per gallon or about 30mls per 3.8 L then spray directly on plants.
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This will probably work as a starting point for you dstjohn99.

Good to know