Backyard Aquaponics
A place to discuss aquaponics

My system is fairly new (about 1.5 months) and I have a few cucumber plants growing but there seems to be an issues with the leafs.

See the photos but I am not sure why they look to be dying. Any advice? I can give specifics on the system and water if needed.

from the yellow leafs on the lettuce i would say the plants are hungry and are also lacking in iron. Iron is something that you have to supplement in Ap systems, this is well documented.

Tell us some more about your system and we should be able to find a solution.
how often are you feeding the fish and with what? quality food creates quality fertiliser for the plants you also need the right levels of fertiliser so you should be feeding enough for the plants. do you have any water quality test strips?

I have a 40 gall on FT and 18 gallon GB with about 10" of media. It is a fill and drain with an auto syphon. I have two gold fish (larger). I think my problem is a few. 1st, my PH was too high 8.25, then also I am just feeding my fish food from Walmart (new stuff on order) and I have no added any supplements to my system.

Currently I lowered the PH, but was WAY too aggressive (lesson learned) an added about 6oz of ph down, which did its job. It took it down to 4.15ph... and so I did some water changes and got the PH back up to about 7.25 (about my normal tap water). But now my ammonia levels were above 8 PPM when got up this morning so I am doing some water changes to get that down. I am guessing the ph change with killed or shocked my bacteria and stopped the cycle.

I good times... nothing has died yet and I am hoping I can get through the next few days without the fish dying...

Its allways good knowing your source water and what you can do with it. sound slike you could of saved some $ by only doing water changes and not messing with pH down.

The aim of the game is to stabilize, so it may do more harm than good constantly changing the water qualities. Also your running a 40:18 ratio when the recommended is closer to 1:2. (Fish tank : grow bed, volume)

Your suppose to have the grow bed be twice the size as the fish tank, I thought I was the other way around?

It has been my understanding as well that you're supposed to have twice as much growbed volume as FT volume. So far that's been an unattainable goal for me, but I'm working on it. Good luck to you!

(Please Note: The order of the ratios quoted below is reversed to that quoted above, ie: gravel:water, not water:gravel)

Wet gravel:water ratios anywhere between 0.6:1 and 2:1 have shown to be successful, with the majority of backyard systems running a ratio towards the bottom end of that range, ie: usually somewhere between the 0.6:1 and 1:1

Here's another discussion that took place re gravel:water ratios a few days ago:

viewtopic.php?f=12&t=26155&p=523163&hilit=gravel%3Afish+ratio#p523163

That said, your plants issues could be because of a couple of issues. The first being that it is a very young system with very little nutrient input. The second being the high pH locking out what little trace elements may be present.

I would take a two fold approach to solving the issue.

(1).

- Remove about 10% of the water from the system into a separate drum etc and treat it with small amounts of Hydrochloric acid to a pH of 6.0

- Retest after a few hours as the pH will bounce back up initially. You may have to re-dose a few times to get the pH to stabilise at 6.0

- During the process keep track of the total amount of acid it took to achieve this constant 6.0 pH so with future treatments you can dose the same volume of water in one hit rather than a few smaller doses.

- Once the pH is stabilised at 6.0 you can then add this treated water back into the main system gradually, ie: in 3 or 4 lots over an hour or so.

- This process will remove the majority of the carbonates from the water being treated. Repeating this process every day will gradually reduce the amount of carbonates in the main system and the system pH should start to drop on it's own.

- When the main system pH has dropped on it's own into the low-mid 7's I would stop treating the system water and just treat any top-up water in the same manner so you aren't always topping the system up more carbonates.

(2).

- Add Seasol seaweed extract (or Maxicrop), initially at 2x capfuls per 500L of water.

- Then at one capful per 500L every week from then on.


These two approaches should rectify the nutrient deficiency issue within a couple of weeks.

Once the system has cycled I would add another few goldfish a.s.a.p.

Awesome, thank you so much!