Yellow plants

[Benicia Bendele]

I have a system that is only 2 months old. My plants are turning yellow. What nutriance can I add to give the lettuce and basil a boost but not hurt the tilapia?

[TCLynx]

What do your water tests say?

Ammonia

Nitrite

Nitrate

pH

and what is your water temperature?

Are the fish eating?

How are the plants turning yellow?  Is it the oldest leaves first or is it the new young leaves?  Are the veins staying green longer and yellowing between the veins?

Knowing why and how the plants are yellowing will help us tell you what you might add to help without hurting your fish.  If you add something that you don't actually need, you can make things worse instead of better.

[Benicia Bendele]

The ammonia is .4
Nitrite and nitrates are higher than my reader
Ph 7.5
Water temp is low 68. We are working on a wood burning water heater, should be complete saturday
I think the fish are eating. The food sinks. The fish are growing.
The yellowing is different. Basil, newer leaves are yellowing, lettus older leaves are turning. The plants are not very large they are only 16 days old from seed.

TCLynx said:

What do your water tests say?

Ammonia

Nitrite

Nitrate

pH

and what is your water temperature?

Are the fish eating?

How are the plants turning yellow?  Is it the oldest leaves first or is it the new young leaves?  Are the veins staying green longer and yellowing between the veins?

Knowing why and how the plants are yellowing will help us tell you what you might add to help without hurting your fish.  If you add something that you don't actually need, you can make things worse instead of better.

[TCLynx]

If your nitrite is off the chart, then STOP FEEDING or you will kill your fish!!!!

Sounds like you may not be fully cycled or you don't have enough filtration to support your fish load or you have too much feed rotting in the tank or something.

If Nitrate is off the chart you probably have plenty of nutrients.  You may perhaps need a dose of chelated iron or maybe some maxicrop with iron to take care of some trace elements and provide some iron to your plants but your system is not fully cycled if you are still seeing ammonia and nitrite readings and that could be partially because your water temperatures are cool.  Add extra air, scoop out any uneaten feed and don't feed anymore till the ammonia and nitrite are both low.

[Benicia Bendele]

I ordered Chelated Iron and it finally came in.  For lettus the only instructions are 10lbs per every acre and do not apply to follage.  My system is 15530 gallons.  Any suggestions as to how many pounds to use?

 

PS nitrates are comming down.

TCLynx said:

If your nitrite is off the chart, then STOP FEEDING or you will kill your fish!!!!

Sounds like you may not be fully cycled or you don't have enough filtration to support your fish load or you have too much feed rotting in the tank or something.

If Nitrate is off the chart you probably have plenty of nutrients.  You may perhaps need a dose of chelated iron or maybe some maxicrop with iron to take care of some trace elements and provide some iron to your plants but your system is not fully cycled if you are still seeing ammonia and nitrite readings and that could be partially because your water temperatures are cool.  Add extra air, scoop out any uneaten feed and don't feed anymore till the ammonia and nitrite are both low.

[TCLynx]

what kind of iron?  I've been using the Sprint 330 and I might put a spoon full of the powder under the water inlet on my 100 gallon grow beds in my high pH system.  The amount to use should be based more on the plant growing space than on the amount of water in the whole system.  How much plant growing space do you have?

what is your pH?

And what are the ammonia, nitrite and nitrate readings now?  Did you start feeding again after the Nitrite got to 0?

[Benicia Bendele]

We have 2 - 8ft by 75 ft 1 ft deep beds.  We ordered Miller iron chelated DP.  The ph is 7.5 ammonia is .6 nitrates are still high but coming down 3.96.  We reduced the feeding and found that we had uneaten food sitting on the bottom of the tank.  That have been cleaned out. 

TCLynx said:

what kind of iron?  I've been using the Sprint 330 and I might put a spoon full of the powder under the water inlet on my 100 gallon grow beds in my high pH system.  The amount to use should be based more on the plant growing space than on the amount of water in the whole system.  How much plant growing space do you have?

what is your pH?

And what are the ammonia, nitrite and nitrate readings now?  Did you start feeding again after the Nitrite got to 0?

[TCLynx]

When I did a search, I came up with the following pdf

http://www.irrigation-mart.com/Documents/Chemicals/ironchelatedp.pdf

Perhaps you can find something in there to help you estimate a dosage.

Sounds like you have about 1200 square feet of plants so you might be able to estimate dosage based on how many spoon fulls they recommend per 100 square feet of nursery plants.  I would recommend the lowest dosage and maybe even a little lower to start and see if it has any effect after several days.  And actually foliar spraying might be a good idea or a combination until the plants catch up.

[Nate Storey]

You have a 15,500 gallon system?  Is that a typo or is your system really that size?  If you really have a 15,500 gallon system dose at 1 tablespoons every day for three weeks, then drop to 1 table spoon 4 times per week and maintain that.

[Jon Parr]

75'x8'x1' equals 600 cubic ft. 600 x 2 GB's x 7.5 g/cu ft is about 9000 gallons of GB, could easily be 15,500 including FT, eh? Nate, is that experience talking on your iron recipe, or following instructions? Is there a way to measure available iron other than plant ovservation? Thanks.

[Nate Storey]

Hi Jon, I guess I didn't read that carefully.  You want to dose on water volume, not growbed volume.  Dosage will be highly variable depending on the algae conc. of the system, so unless you have a lot of fancy equipment that I can't afford, the best way to dose is hit a baseline and then watch your plants very carefully and respond to nutrient deficiencies.  Or, if you're commercial, do tissue analysis and respond.  That dosage rate is based on my experience.  It should help hit baseline on a per gallon basis and then allow you to drop your rate and respond as plants begin to show deficiency.  You don't want to over dose, but more is better than less when it comes to iron.  In populations with high populations of algae, your iron will dissapear fast, and much of it will become plant unavailable in the process of algal assim. and decomp.

While you initially dose on a per gallon basis, down the road as you expand your plant production you'll want to switch over to a steady biomass basis for dosing- again that depends on watching your plants, tissue analysis, or water testing.  Water testing is not great though, I'm not sure most testers can separate ferrous, ferric and amino-bound (chelated) iron in tests, so the best way to monitor is 1) tissue analysis, 2) visual deficiency monitoring, and 3) water testing. . .   Any way, I'm commercial so I choose to stay ahead of the curve and dose at a steady rate that works for me.

[Benicia Bendele]

Thanks for the info, I will start the process tomorrow.  When you say look at the tissue what exactly am I looking at the roots?  What am I looking for discolorazation?

Nate Storey said:

Hi Jon, I guess I didn't read that carefully.  You want to dose on water volume, not growbed volume.  Dosage will be highly variable depending on the algae conc. of the system, so unless you have a lot of fancy equipment that I can't afford, the best way to dose is hit a baseline and then watch your plants very carefully and respond to nutrient deficiencies.  Or, if you're commercial, do tissue analysis and respond.  That dosage rate is based on my experience.  It should help hit baseline on a per gallon basis and then allow you to drop your rate and respond as plants begin to show deficiency.  You don't want to over dose, but more is better than less when it comes to iron.  In populations with high populations of algae, your iron will dissapear fast, and much of it will become plant unavailable in the process of algal assim. and decomp.

While you initially dose on a per gallon basis, down the road as you expand your plant production you'll want to switch over to a steady biomass basis for dosing- again that depends on watching your plants, tissue analysis, or water testing.  Water testing is not great though, I'm not sure most testers can separate ferrous, ferric and amino-bound (chelated) iron in tests, so the best way to monitor is 1) tissue analysis, 2) visual deficiency monitoring, and 3) water testing. . .   Any way, I'm commercial so I choose to stay ahead of the curve and dose at a steady rate that works for me.

[Nate Storey]

You're looking for interveinal chlorosis- yellowing of leaves between the veins, especially on old growth leaves.  Iron is mobile within the plant, so new leaves won't always show chlorosis, look on older leaves.