Backyard Aquaponics
A place to discuss aquaponics

To begin thanks in advance for any and all help. First let me explain the issue and than I will give some background information. My 7 plants, Basic tomato, an established big boy tomato up rooted from soil outside, green pepper and 4 strawberries, are all dying except for a very small amount of new growth. All the plants, except the big boy, were all bought at Walmart about a month ago. The Pepper plant had a small pepper on it. it has not grown at all. most the leaves on all plants are wilting. Not showing any other signs of issues. i.e. yellow or black leaves, color change, or spots.

Ok so a little background. About 10 months ago I started a system. I started with about 2 dozen gold fish in my 40 gal tank. It is a basic flood and flow system using fish gravel as the medium. I tried several other systems before this but for different reasons none of them worked for my situation. Anyways most of the goldfish died pretty quick. only about 6 survived and grew pretty quick. I tried several different plants. Egg plants, tomatoes, strawberries, peppers, lettuce. Some from seeds and other from store bought plants. It was weird, none of them grew. they just stayed the same for months. one by one, weeks apart, a plant would just die immediately with no warning. Suddenly and with in hours would go from a full plant to literally nothing. The other plants would be fine for awhile. Eventually the last plant died. None of the plants ever produced fruit or grew. I eventually added a small frog and a sucker fish to help the cloudyness of the tank. That part worked well. After all the plants died I stopped flowing the water and let the tank be. The water got very cloudy. About a month ago I dumped the fish pebbles out and got expanded clay pebbles. I also bought 20 fish. 12 of them were small gold fish and the other 8 were a tetra. All of the tetras died pretty quick and about half the new goldfish including yesterday my biggest goldfish from the previous batch 10 months ago. He was about 8 inches long, kinda sad.

Because of goldy dying I am jumping into action. Since starting the system I have done a lot of research but am constantly getting mixed messages and having a hard time getting my system working.

With the first system I had the flood and flow on a 30 min on 1 hr off interval. I have read a lot of disagreeing info on how long to have it on/off. I currently have it set to 30 min on and a hr and a half off.

The lights I am using are led bulbs. 6 of them are small about 20 watts and I have one large one about 60 watts if I remember correctly. They are currently on a timer for 12 hours on/off. I have tried adjusting the height several times with no noticeable changes to the plants.

I am stumped. The fish don't seem to have any visible issues and they are definitely not sluggish. I do feed them a lot, three or four times a day, but the cycle seems to be working well. The plants just don't seem to be growing or absorbing the nitrate. A lot of forums suggest to add more plants but if the ones I have are wilting and not growing I don't see how adding more plants could possibly make things better.

ammonia seems to be about 0.25
Nitrate at least 200
Nitrite about .5
Hardness very hard
moderate alkalinity
ph about 6.8

Any help would be much appreciated!!!!!!!!!!!!!!

Hi wrestlemy69,

>> I have read a lot of disagreeing info on how long to have it on/off.
>> 30 min on and a hr and a half off

the perils of forums. Basically I would bring your timer back to 30/30 - why ? Because based on what you wrote you are probably not getting enough filtration and possibly aeration, so the GB flow is for the fish. However if your system dries out quite a bit it will probably help the plants as well. [ you can have it ON for as much as you like because that is when it is filtering. ]

Also if your bed dries there is less opportunity for the bacteria to do its thing, so I would aim for more water in the GB more often. Better circulation and aeration for your fish as well. Though your nitrates are up so bacteria look OK at face value.

Q. what volume is your grow bed/planter ?

for 40 gallon you have 200L so you would need around 20 gallon of media to get 0.5:1 (GB:FT)
I cannot comment on an indoor FT but can say that even with just 200L GB to my 700L IBC FT I can clear the water in 24-48 hours on a 30-30 cycle.

Q. Cloudy due to algae or cloudy due to ??? If not algae then may be your fish food.

Q. what is the height of your water in the GB when it is full ?

Is it below the surface or is it at the surface ? else they get waterlogged.
The recommendation is 5cm (2") below the surface

Comment 1:

You are presumably indoors so how good is the light on the plants (rather than the FT).
And what are you using - are they plant/hydroponic LEDs or jut standrad LEDs.
If standard LEDs then you are probably not getting the full light spectrum plants need.

Can you put it by a window ?

Ammonia is up but you have nitrates so if they come from fish then the cycling aspect is covered.
Only issue would be if you have added plant food or fertiliser with nitrogen in it when the plants got sick?

You have to get your nitrates down - not great for the fish. Get some replacement water on the go and take a 5-10L (2 Gal) watering can and water some other house/garden plants with it. Replace with same volume new water. Do this for a while rather than a sudden water change. Try and do it enough to get everything back down low.

Not good at indoor plants but think about something that will grow and suck nutrients (nitrates).
Maybe worry about the Fish rather than the Veg for time being.
You basically want maximum green leaf growth.

Ferns could be an option - but not sure how hungry they would be.
Grow your chilli bush in a normal planter with soil next to it all or on the window and just use AP water from can.
If it dies then you have a light issue.

finally - feed your fish only once or twice a day. Stop doing it for a few days initially.
fish food might be making your water cloudy.

Finally I guess you are in Arizona so maybe less of an issue - but being in a house with heater / AC on can dry plants out.
In which case more wetting of the GB will help.

Can you take some pictures of the plants with regular lighting - not the leds. That might reveal some nutrient issues. Pics of the fish tank that would give us some info on how it's all setup would be good as well.

>> 30 min on and a hr and a half off

I read that I should do it this long so the roots don't stay saturated. But per your advise I have turned on constant flow for the time being to try and flush the system. My next biggest fish died this morning.

Q. what volume is your grow bed/planter ?

2ft 10in long x 6in wide x 6in deep

Q. Cloudy due to algae or cloudy due to ??? If not algae then may be your fish food.

Not algae. I have a sucker fish and a frog that take care of that. The system was left as was with no flowing water for about 3 months. It got pretty cloudy than and has not cleared up. Also when I added the plants and started the system again there was some dirt remaining on the roots so the water got "dirty". It has cleared up some. But still like a brownish color.

Q. what is the height of your water in the GB when it is full ?

It is about 2 inches below maybe a bit more. Hard to calculate because it is sitting at a slight angel and pools higher in some areas than others.

Q.You are presumably indoors so how good is the light on the plants (rather than the FT).
And what are you using - are they plant/hydroponic LEDs or jut standrad LEDs.
If standard LEDs then you are probably not getting the full light spectrum plants need.

Yes I am inside. I meant to post a pic of the whole setup but forgot to insert it. Will do it now. They are blue and red plant leds. That is why the pics have a purple tint to them.

Q.Can you put it by a window ?

No. Wish I could.

Q. Ammonia is up but you have nitrates so if they come from fish then the cycling aspect is covered.
Only issue would be if you have added plant food or fertiliser with nitrogen in it when the plants got sick?

I did add a small touch of miracle grow a month ago but not sure that had much of an effect beside tinting the water a bit. The test all seem to be the same.

Q.You have to get your nitrates down - not great for the fish. Get some replacement water on the go and take a 5-10L (2 Gal) watering can and water some other house/garden plants with it. Replace with same volume new water. Do this for a while rather than a sudden water change. Try and do it enough to get everything back down low.

I hate doing this but will give it a try. I do have a strawberry plant from the same batch in a soil pot. It is doing very well. I hope the water doesn't harm this lol.

Q.Not good at indoor plants but think about something that will grow and suck nutrients (nitrates).
Maybe worry about the Fish rather than the Veg for time being.
You basically want maximum green leaf growth.

Everything I have read says that fish can handle a high amount of nitrates. Bluegill and tilapia about 400. Not sure of a rating for goldfish. Also because my test only goes to 200 im not exactly sure how high mine is.

Q.Grow your chilli bush in a normal planter with soil next to it all or on the window and just use AP water from can.
If it dies then you have a light issue.

I will have to try this.

Q. finally - feed your fish only once or twice a day. Stop doing it for a few days initially.
fish food might be making your water cloudy.

I have done this in the past and will take your advice.

Q.Finally I guess you are in Arizona so maybe less of an issue - but being in a house with heater / AC on can dry plants out.
In which case more wetting of the GB will help.

The heater is rarely on. The house (for now, winter) stays about 65 degrees. In the summer I keep it about 70. The AC is on a lot. It has to be. I am in norther Arizona at about 3000 feet altitude. Not sure if that affects anything.

Comments: I ordered some Maxicrop and plan on buying a dozen worms as per a suggestion I read on a forum for someone who was having a high nitrate issue (but there plants and fish wernt dying)

The biggest thing I don't understand is why there is new growth that is doing ok and all the old established growth is dying. The changes I made (light adjustments, water 30 on hr and a half off, and extreme feeding) seem to have a good effect on that but nothing else.

I think the combination of a very shallow grow bed and the large amount of fines in the fish tank is causing the plants to have root rot issues. The fines can coat the roots and smother them. It's more common in DWC setups. Light levels could be contributing but this doesn't look like a nutrient issue. I also noticed that the strawberry plants are too low in the media - you want the crowns higher - even with or above the surface.

AP setups don't use pebbles in the fish tank, potentially it could work but it becomes more difficult to see what's going on and to clean. Does your aquarium have an under gravel filter?

I have seen shallow grow beds work, granted mainly with herbs.

What do you mean by fines?

Would the worms help the root rot issue?

There are pebbles and objects in the fish tank because the women won't let me have a fish tank with out it being pretty. Although the merky water is aggravating her lol.

Light levels? To low. I thought it might have been a over kill.

The strawberry plants are low because they have very short and tiny roots and that was the only way I could get water to them.

The tank has no filter system what so ever, except of course the clay pellets.

Root rot wouldn't explain why there is new growth but the established part of the plant is dying.

By fines I'm talking about very fine solids.

The worms might help the root rot issue but no guarantees they'll cure the problem.



You may be right. On the light levels it's tough to tell with the new LED's since I haven't used them. I suggested light but anything that stresses the plant and makes it weaker, will make it more susceptible to disease.



It sometimes starts out this way because the rot doesn't always affect all the roots at first. I also notice that the top of your tomato plant is wilted so it's not just the older parts of the plant that are being affect. Something is affecting the water transport and uptake at the roots seems a likely culprit since the stem looks pretty healthy up to where it wilts.

Losing the older strawberry leaves could just be due to the lack of roots and the plants might recover as they grow and put out new roots (you'll still lose the leaves but the plant will grow new ones). I did notice a darkened fringe on one of the strawberry plants that could be either potassium or magnesium deficiency - I think it's more likely a potassium deficiency. It's in the top photo that has the tomato plant with a strawberry that's shaded underneath.

Is there a way to up root the plants and check for root rot? what am I looking for?

As for the lights, they were like 2 dollars a bulb. This type of light is so new to the market and unused I cant find much of any information on them or the "proper" way to use them.

As for the strawberries. That just popped up this morning. Luckily I ordered the maxi crop last night. Unfortunately it wont be here for another week.

Any short term quick solutions for the potassium. One forum suggested banana peels?

>> I read on a forum for someone who was having a high nitrate issue (but there plants and fish wernt dying)

OK. The primary issue here is a lot of information pertains to outdoor systems with 700L+ fish tanks and 300L+ grow beds. That advice may not translate so well into an indoor aquarium scenario.

your GB is 6" (150mm) where most full size AP grow beds are 250-350mm (10"-13").

you are running an aquarium - so your basic AP strategy will be 50% AP and 50% aquarium.


>> Everything I have read says that fish can handle a high amount of nitrates.

you quote Nitrates for a aquaculture/full size AP level setup where these levels are going to be much more significant in an aquarium level setup. Small changes in a full-size AP = big changes in an aquarium as you dont have the water volume to buffer or lag the effects.

Nothing in excess is good, particularly in an aquarium - around this forum 'high nitrates = an immediate get them down from the first responder'. They are not ideal for fish and can actually cause issues for vegetation nutrient uptake.

<Scotty435> I think the combination of a very shallow grow bed and the large amount of fines in the fish tank is causing the plants to have root rot issues.

Scotty raises an interesting quirk...
in a *healthy* AP with good oxygen and media circulation the roots will actually thrive in the water and the plants will grow really well (that is also why DWC deep water culture etc work).
in soil container gardening over-watering => saturation => wilting and dead plants.


Q. when you add plants to your GB did you wash the soil off your roots first ?

If the water is not clear for whatever reason it comes back to filtering.
You need a strategy to remove all the fine material and solids from your system.
Adding a dozen worms is probably not going to be the answer.

For your wife's benefit maybe a small aquarium box type filter that you will have to initially flush every day will help with the main tank. The advice on regular small water changes was made previously.

Maybe try some lettuce or herbs. And have the Chilli plant in a pot beside.
I struggle to see the benefit of a tomato plant in your situation.

[ If it were my system I would run the aquarium for the fish first and the plants way back in third. ]

There are some options such as wood ash but you need to watch the pH - https://www.growveg.com/guides/using-wood-ash-in-the-vegetable-garden/

It makes sense a larger set up makes it easier to make changes. Never thought about it that way.

Hmmm. Damn nitrates! lol. I am going to try and dump refill half the tank later.

Will have to see if I have a filter laying around.

The older tomato plant is from outside. I brought it in to keep it alive. Had no where for a pot and already had the set up, (just wasn't set up) so I decided to revive it and try to get it going. And instead of having just one plant I bought a few plants to add to the system.

I appreciate you guys for your help.

I'm still a RANK amateur at AP but as soon as I read no filter and Miracle grow, I thought to myself those can't be good. Am I way off base?

I took the no filter bit with a grain of salt because he does have a grow bed which will act as a filter and as long as he has enough filtration of this type for the fish he has it would be OK. If not then it's a problem, anaerobic zones develop and things head south.

As far as the miracle grow - I don't know what form the nitrogen takes in this and it could be a problem. Some fertilizers can be counterproductive to establishing the bacterial colony, others can cause problems for the fish if the system isn't already cycled. Occasionally it makes sense to use a fertilizer of sorts to carry a system through a light stocking period, especially once the system is cycled and if it's in a form that feeds the right group of bacteria in the grow bed (ammonia and nitrite oxidizers).