Backyard Aquaponics
A place to discuss aquaponics

Hello everyone, i'm Matej from Slovenia and i've been interested in AP for 5 years now and i love it, i'm a student of horticulture but my school provides no knowledge even about the RAS system and i'm happy i found your forum as it is far more knowledgeable


i've built a small system a year ago i think, it's a small cabby growing basil. runs on 120L of water RAS style, deep water culture but recirculative

water temps are around 22-25°C
ph 6.5-6.9 adjusted with KOH and Phophoric acid at the start
EC 0.7

i have one gold fish, three Pterophyllum scalare, two Trichogaster trichopterus sumatranus, four Platys (Cyprinodontidae), four Silver Sharks, and one cleaner living in my aquarium

let's have a look
now i'm having some problems, the leaves are turning yellow for quite some time and i can't figure it out, is it the lack of growbed (i'm using mediumless), or are the temps the problem? although i've grown in RAS with no problems with temps over 25°C

ph is rock steady, i only bring fresh water every week i don't drain anything out, i add about 10L of aged tap water once a week
could this be the problem? i'm feeding them some commercial food from a pet store, and it contains a lot of NaCl as it is very salty if you taste it, maybe the salts builded up?

i tried feeding them red composting worms, but only the goldfish had the hunger for them....would love to have another suggestion on what to do with these tropical fish food?

i'm having some problems working with this forum, but i promis i'll learn in time

here are the plants suffering from a lack of something, i don't think it's Mg or Fe or something similar, looks like a pH problem that happens in RAS when the ph gets too high or too low(over 6.0 and under 5.5)

i would love to have some comments and i'm looking forward reading them!

have a good and peaceful day!

Hi Matej! Welcome!

Yellowing leaves and sparse roots are probably a nutrient deficiency as you are guessing. Your pH sounds fine to keep from locking the nutrients, but fish food doesn't necessarily provide all the nutrients your plants would like. Some people (like myself) are finding the need to supplement the nutrients with a periodic dose of chelated iron or a seaweed concoction the Aussies call Seasol. I've also experimented with adding phosphate when I see general yellowing, and that has helped, too. If new leaves are yellowing, but their veins are still green, then you need the chelated iron, and that will provide other micro-nutrients, too. Because you are thinking the roots are not growing, I'm inclined to suggest a small amount of phosphate. The one thing you probably don't need is nitrogen, of course.

If you are concerned that salt levels are too high, there are salt tests available in stores that supply things for ponds. Anything under 3-4ppt probably won't hurt most plants. Or you could just do a water change and see if things improve.

For fish food, you could try growing your own duckweed, or if you are inclined to spend the money, they might like frozen worms. Some folks are making their own fish food, and there is a whole thread discussing all the delicious things to put in it.

Here is a picture of one of my root systems that I pulled out of the gutter system when I transplanted. I must be doing something right

I wonder if its a Magnesium Deficiency? I know when I toss a tad bit of epsom salt in the mix it greens up. Magnesium Sulfate

http://www.hbci.com/~wenonah/min-def/list.htm

i love this site already!! thank you janet for a quick reply!

do my fish eat duckweed??i can easily get it, i've hear off frozen worms but i doubt my local shops have then, never seen a fridge there, or are they just frozen dried?

i do have some algea extract in stock, it says it contains red-algea
it's used as a soil-supplement, what do you think?

i'll finally buy those Na tests, thanks for incouragiing me!

slice, i've read a simmilar thing somewhere here, suggesting adding epsom salts, but i'm not sure this is a Mg def, since it should be seen on the bigger lower fan leaves first, don't you think so? my chlorosis is harder on the upper new leaves, that's why i have doubts adding eps. salts

awsome root ball, i bet the Petroselinum crispum tastes good in AP! very nice
i'm planning to set up a small(3-5000L) pond back at home this spring, and you ppl have lifted my spirits up to the sky, great work!

Molj I was just stabbing at the problem here. I am really not sure what the def would be. I am still learning

And yes the parsley does taste good but that plant kinda died.. The tomato plant removal destroyed the parsley sadly..

Tomatos vs Parsley
Tomato 1, Parsley 0

saying that because my tap water is high in mg and cal, and i usually don't have to supplement mg in RAS with the same water and mineral ferts with no cal and mg

slice oppinions lead to a conclusion, i love it just keep it comming

i remembered why i like mediumless, if i remove any of the plants, the other's roots stay pretty much untouched
maybe the other AP growers use round smooth stones for the same reason, the lant's roots don't fix themselves on the stones as they do on lava rocks
+ river bed gravel is far cheaper then lrocks, at least in our place you can get lava rocks only for BBQ, and that's what i used for my underwater biofilter
do i have i point on the rocks?tell me what do you think please

You can get freeze dried worms that would not need a freezer, but try the duckweed first to see if they like it. Free is nice. Freeze-dried is expensive. Goldfish should eat duckweed, but I'm less sure about the other fish. I'm very surprised your angelfish didn't like earthworms--perhaps the worms were too big and wiggly. Try cutting them up first. When my father bred angels, that's how he conditioned them for breeding.

Algae extract might be nice to add, just do a little at a time in case the fish don't like it. I tried making a kelp tea, but my fish objected (sulked at the bottom of the tank and wouldn't come for breakfast), so I had to do a fast water change. I think I just used too much.

Welcome molj!

What is the water circulation like in that box? Do the roots get any bubbles to keep them aerated?

Different folks ahve different reasons for what we use...

We use gravel because it's cheap.
We use hydroton because it's nice to work with and weighs less.
We use lava rock because we can dig it out of the nearby volcanic fields and it's free. (DTHawk!)

Janet if I had a truck I would go dig pumice

Currently I buy the lava rock for 1.50$ a half barrel. Buy truck or not

Hi Matej, great that you have jumped in with pictures we like that

For the roots of the plants, they may need some extra aeration to prevent the root rot.

another all purpose additive for the plants is pulverised volcanic rock. Usually a grey powder that contains a good mix of minerals that the plants can access. Make sure it is ONLY pulverised rock, with no sneaky chemical additives that might harm your fish.

dave: water is changed practically every minute in the upper bucket, that pump is rated 1600L/h at 1m, thank you for the warm welcome

i use no sort of bubblers or air pumps, i find them unnecessary if the water flow is adequate(good water pump), and there's a lot off flow in there it can't be that. i've seen rot in RAS and this is not it, the plant would die ages ago if this was root rot, remember it has been like this for several months

i really am most positive that this is an nutrient issue not an DO one

vulcanic rock ash? that sounds pretty exotic for our supplyers:)

i'm gonna go with duck weed first, i'm not so sure about those algeas, because i used them once in my system and they clogged the filter and the tubes, nothing good from them, so i'm guessing u'r talking about different algea

is it the green one ? i've read and heard that it's used as food for general perpouses, even for feeding the human kind, is that what you ment janet?thanks for clearing things up about the medium!

jaymie
pulverised volcanic rock ---> is this called zeolite? like for cleaning water? and for health perpuoses?
btw, i'm glad i'm pleasing ya too

another question, where do you buy algea extracts and vulcanic rock etc.?

thank you all for pitching in, have a good day!

a few pics of my friends, each of them a different story

no, the stuff I'm talking about is sold here in Australia, something similar should be available anywhere there used to be volcanoes
http://www.minplus.com.au/index.html