Backyard Aquaponics
A place to discuss aquaponics

Hi Everyone,

First post, so please forgive my ignorance. I just started up my first aquaponics system about 2 months ago. The system includes an 18 square meter DWC bed, 3 square meters of lava rock media beds. 2 x 1000 L fish tanks, and 600 L sump. I guess I probably should have started with something a bit smaller.

I have been reading up, but still I'm struggling to understand the water chemistry.
*Thanks in advance, if anyone can suggest how to adjust the water premasters, to correct the imbalance as per the images.

Problem
The plants seem to be growing quite fast, but I'm pretty sure I have a nutrient deficiency. About 30-40% of the plants have a mottled yellowing on the leaves between the veins. However, the rest of the plants look pretty ok to me.

After the ammonia and nitrite cycled down to zero, I added about 50 goldfish of various sizes, and 70, very small silver perch (30mm). But I don't think they were producing enough nutrients, so I have been supplementing with the following; chelated Iron, calcium carbonate, potassium carbonate, Epsom salt and power feed (seaweed and fish emulsion), plus a little bit of bicarbonate of soda.

Water Parameter
The water parameters seem out of balance, based on what I have been reading. But I don't really understand how to adjust them, without raising the General Hardness, which seems way too high. The KH also seems way too low.

Water Temp; 18c Day / 14c at Night
pH; 6.5 (but not very stable. I need to keep adjusting it up with calcium and potassium, to stop it dropping).
KH: 2 drops (35.8 ppm, according to the chart)
GH: 12 drops (214.8 ppm, according to the chart)
Iron: 0.4
Calcium: 125ppm, (If I have read that correctly)
Ammonia: 0
Nitrite: 0
Nitrate: at least 160ppm (or more, its at the end of the colour chart)
EC: 1.0

Dang, looking very nice!!! Awesome first system.

ABSOLUTELY FIRST STEP:

Chill out and relax a bit. A new system will not be stable, and chasing a bunch of moving targets will stress you out and potentially kill your fish.

Okay, the following may be helpful. Items to stress about - ammonia, nitrite. These will kill your fish quickly. It looks like they are under control, but be sure to check them regularly, maybe weekly until your system has been stable for a few months.

pH, if it is dropping then yes by all means keep it in a desirable range (6-8). I suggest using potassium bicarbonate as this will supplement potassium and raise your carbonate hardness which will help. Also, put some shell grit or crushed egg shells (boiled) in a sock or nylons and put them in your sump, or under a grow bed water inlet or similar to help buffer pH and raise carbonates.

Don't sweat anything else. Hardness is not a big deal, it means you have calcium and magnesium available for your plants among other things, but it is certainly not worth worrying about at this point.

Try not to add anything other than fish food. Your plants probably have pH or similar nutrient lockout and will get better as things stabilize.

Also, do you have an iron test kit? If not, then you don't really know if you need to add it, or how much or how often. I've run systems for a few years before I started adding iron and they were fine. I have strawberries that look like they have severe iron deficiency, but it is really that they are getting too much water and the corn is stealing all their nitrogen (planted in the same bed).

Yes, starting small is good but it looks like you are all in now anyway. Don't waste your money buying a bunch of supplemental nutrients as they are likely unnecessary. If you're gonna do that you may as well go hydroponics. Better to invest in quality commercial fish feed like Purina Aquamax or similar.

It also sounds like you don't have enough fish for the system yet, but that will come as they grow. That's why you typically want to stay with leafy greens and similar plants that don't need a spectrum of nutrients, then as things mature work up to fruits and vegetables, etc.

Your plants look pretty darn healthy, so I think you are doing well! Enjoy the ride.

I agree with those comments , I think it is looking pretty good.

Yeah I have to agree with you, everything is looking fine and excellent.

Thank you all for replying to my post.
Especially big thanks to dstjohn99!!!
Great advice, I will focus on making sure the fish have good nutrition, and look for a source healthy food.
I will post some new photos soon.