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| Can You Have Too Much Nutrients http://byap.backyardmagazines.com/forum/viewtopic.php?f=1&t=28180 |
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| Author: | JeffS [ Jan 27th, '17, 12:12 ] | ||
| Post subject: | Can You Have Too Much Nutrients | ||
I have a 600 gallon IBC system that's 3 years old. First couple of years everything grew well but lately nothing wants to grow. Seedlings die, more mature plants' older leaves yellow and fall off. I sent water out for testing and it came in with high nutrient #s and nothing detrimental otherwise. Can excess nutrient be toxic?
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| Author: | scotty435 [ Jan 27th, '17, 12:59 ] |
| Post subject: | Re: Can You Have Too Much Nutrients |
JeffS wrote: Can excess nutrient be toxic? Yes, definitely. Hmm, initially I thought your sodium and chloride levels were too high but The chloride is only 0.5 ppt so that's not very high  . I might have to give this another look later.
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| Author: | ebeuerle [ Jan 28th, '17, 05:12 ] |
| Post subject: | Re: Can You Have Too Much Nutrients |
+1 on what Scotty said. My take - your sodium levels are killing your plants... anything past 50-75 ppm is usually deadly to plants and you are sitting at 212 ppm. At this point, I would suggest a 20-30% water change to reduce all the levels of nutrients (potassium/cal/mg) are high as well but at least they are within the right ratios (so pat yourself on the back for that!). Also, have you had a water test on your source/top up water supply? It would be good to know what you are adding back in when you replace the water loss from evap/transpiration and when you do water changes. |
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| Author: | scott_dc [ Jan 28th, '17, 08:10 ] |
| Post subject: | Re: Can You Have Too Much Nutrients |
The "percent of total salts" doesn't add up to 100%. What's missing from the report? That might be toxic to plants. 400 ppm potassium seems high (2x that of sodium) but I don't know what levels of potassium are toxic. Many purposefully add about a thousand ppm of sodium and chloride, myself included, without much issue to fish or plants. |
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| Author: | scotty435 [ Jan 28th, '17, 11:03 ] |
| Post subject: | Re: Can You Have Too Much Nutrients |
Quote: Many purposefully add about a thousand ppm of sodium and chloride, myself included, without much issue to fish or plants. That's why I hesitated to blame the sodium and chloride even though that was my first impulse and even though Eddie is correct in terms of what others claim to be toxic in solution. It's common to run 1 part per thousand of sodium chloride to help fish with stress and to build a slime coat. That's twice what the level is here. We do much more than that when salting for disease although anyone who's done this for very long can see the difference in the plants as many plants do suffer with this treatment. I think the solution may be just to dilute this down at least by half but look at the incoming water as suggested and determine what other than sodium and chloride, are likely to be the cause. Before you try this, if you could post pics of your plants and system that would be helpful Jeff  . We also need to know the water temp because this has an effect on seed starting.
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| Author: | JeffS [ Jan 28th, '17, 11:39 ] | ||||
| Post subject: | Re: Can You Have Too Much Nutrients | ||||
I'm attaching the recommended levels but I'm not sure what type of growing these #s are for. Also a few pics .
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| Author: | scotty435 [ Jan 28th, '17, 11:48 ] |
| Post subject: | Re: Can You Have Too Much Nutrients |
Can't tell much from that set of pics, I need some close ups and some farther back shots on these to see which part of the plant is affected as well. Don't forget about the water temp and while your at it what has your air temp been like where the plants are? |
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| Author: | JeffS [ Jan 28th, '17, 11:56 ] |
| Post subject: | Re: Can You Have Too Much Nutrients |
I've pulled all the affected plants which was almost all of them. The water temp is maintained at 70F. The symptoms are older leaves affected mostly. They turn yellow quickly without any indication of veining. When I say quickly I'm talking a day or two. I've even lost potted plants that I was feeding with the fish water. |
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| Author: | scotty435 [ Jan 28th, '17, 16:56 ] |
| Post subject: | Re: Can You Have Too Much Nutrients |
It's too tough to narrow it down at this point so I'll just give you what I'm thinking. I think you may have more than one thing going on. Even though mostly the bottom of the plants are affected I'm leaning toward a waterborne disease problem because of the timing and because you mention that all the plants are affected and because the potted plants watered with this water died. The picture of the lettuce leaf looks like either a bacterial or fungal wilt. Pay attention to the root section of any new plants that you have to pull because of symptoms like this. Do they look good and healthy? You may want to cut a cross section through the roots to see if there is any rotting through the root. Make sure that you sterilize the knife you use if you plan on using it again in your system for harvesting or whatever. Increase the aeration if you see root rot. The other photo actually made me think of spider mites because they cause yellowing and stippling of the leaves (sort of a sand papery look that this photo has) - unfortunately the photo is not good enough to really tell much  . It could also be disease or nutrient deficiency.----------- The only time I start seedlings in the AP system is in the summer. Your water temps are probably right around where mine get to in June so starting in system might work better for you. You may want to consider starting seedlings separate from the system and then transferring since this helps them past some early problems like damping off and allows you to space the plants as desired a bit easier than sowing seeds. The other reason I'm suggesting this is that you won't be totally dependent on seedlings from the AP if this is a disease and you might have some alternative treatments you want to try without any disease already having a head start. Obviously you don't want to water these with your system water. How hot is your growing area during the daylight. Is this in a greenhouse or a building without sunlight? I know that's not much to go on but it's a start. If you have something like this again, post up some good pics, the sooner the better and we might get a better idea of what's going on. If I were dealing with what's going on in your system, without really knowing for sure what's going on, I'd do these things - 1. Increase the aeration (depending on how much aeration you have now). 2. Reduce the nutrient concentration by about half. and maybe the next two 3. Start plants outside the system and transplant in. 4. Inoculate with beneficial organisms before planting into the system. I usually don't suggest this but it's worth a shot. Hope this helps. |
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| Author: | JeffS [ Jan 29th, '17, 00:56 ] |
| Post subject: | Re: Can You Have Too Much Nutrients |
Thanks for everyone's help help. Seedlings are all started in a separate basement system and are healthy until transplanted to greenhouse, even cool weather plants. The greenhouse gets a minimum temp of 54F and maximum in the low 80s when I fire up the wood burner. I use HPS and MH grow lights during the night hours to help compensate for outside temp changes along with a thermostatically controlled propane heater as a backup. Temps are monitored so I can make sure they don't get too cold. I'm not sure why the nutrient levels are so high. I only add potassium hydroxide and garden lime when pH is low and that rarely happens. I actually lower the pH sometimes so I can add those nutrients. I also add the occasional Epsom Salts. My top off water has been ground water that gathers around the in ground sump (keeps the sump from floating). That may be the problem. I only used tap water in the past for filling and topping off after a settling period. I'm going to send off a ground water sample next week. Interesting that MSU doesn't offer any info on aquaponics. |
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| Author: | ebeuerle [ Jan 29th, '17, 01:25 ] |
| Post subject: | Re: Can You Have Too Much Nutrients |
@Scotty - yeah I have learned my lesson on salting the tanks with NaCl. Now I only use potassium chloride or other chloride compounds that don't add sodium. I know lots of folks recommend it - including myself but not anymore due to all the trouble it causes the plants. @JeffS - I wouldn't ever use groundwater in your system. The potential for contamination by animal waste, soil bacteria/fungi, as well as heavy metals can result in the issues you describe. While the high sodium and chloride levels are probably not completely to blame, they are most likely putting additional stress on the plants and a 30-50% water change using the tap water should reduce the levels significantly. I would suggest testing your tap water and deciding if it's okay to use as top up water or start collecting some rainwater. The other option is using an activated carbon filter with the ground water to try and filter out as many contaminates as possible. Scotty has some great suggestions as well. |
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| Author: | scotty435 [ Jan 29th, '17, 03:25 ] |
| Post subject: | Re: Can You Have Too Much Nutrients |
As an add on to what was just mentioned - Expect a carbon filter will help with chemical but not with bacterial or fungal issues. |
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| Author: | JeffS [ Jan 29th, '17, 03:27 ] |
| Post subject: | Re: Can You Have Too Much Nutrients |
Water change sounds like a plan. Unfortunately winter is setting in and the only water source to the greenhouse is an above ground hose so right now everything is frozen. Next day above freezing I'll get that done. I only have 100 top off reserve so it'll take several dosings. Meanwhile just out of a need to know I'll send in the ground water for sampling. So would you waste the nutrient rich water or spread it over the yard gardens for next seasons plants? |
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| Author: | scotty435 [ Jan 29th, '17, 04:14 ] |
| Post subject: | Re: Can You Have Too Much Nutrients |
I'd probably use it in the landscape/gardens. |
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| Author: | scott_dc [ Jan 29th, '17, 08:39 ] |
| Post subject: | Re: Can You Have Too Much Nutrients |
Note: 1ppt salt is 1000 ppm NaCl, which is about 400 ppm Na+ and 600ppm Cl- |
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