corn plants turning brown on bottom leaves.

[Ken Richardson]

I have not had much luck growing corn for some reason. It starts out very well gets about a foot high then the bottom leaves start turning brown and dieing. I have corral pieces for calcium, add iron to the bed which is a little over a year old now. The water is a very nice amber color and my goldfish are getting the size of small koi. I also do not have luck with lettuce. I have basil, okra, green beans, squash, brocoli, cherry tomatoes, radish, plus green grapes, two avacodo trees, date tree, a succulent of some kind and a brain cactus. The ph is 6 and I have nothing to measure ammonia or nirates with. Any clue? Also it is indoors with temp between 75-80F and gets both sunlight and grow light. The substrate is a mix of hydroton and large perlite. Flood and drain system. I have never added seaweed extract to the system either.

[Rob Torcellini]

You may want to check for root rot. Corn needs very little moisture. I grow corn in my fields for silage and any place where there's a low area and has a high water table, the plants usually only grow to about 1/2 height. The plants where it's high and dry do the best. You could try cycling your grow bed less often....maybe once per 2-3 hours....or longer?

However, I have seen one system that had corn in it, but I'm not sure how they did it.

[Ken Richardson]

Thanks Rob, I thought that was a possibility, so I guess I wont be growing corn.

Rob Torcellini said:

You may want to check for root rot. Corn needs very little moisture. I grow corn in my fields for silage and any place where there's a low area and has a high water table, the plants usually only grow to about 1/2 height. The plants where it's high and dry do the best. You could try cycling your grow bed less often....maybe once per 2-3 hours....or longer?

However, I have seen one system that had corn in it, but I'm not sure how they did it.

[Rob Torcellini]

Don't give up on it! Half the fun is experimenting! ;-)

[Ken Richardson]

I havent even though I said that. One of the bigger ones is trying to grow and seems to look like it might make it.

Rob Torcellini said:

Don't give up on it! Half the fun is experimenting! ;-)

[Harold Sukhbir]

After one month of growing plants in my barrel system I've realized that finding a balance with flow rates for different plants mixed into one grow bed is quite a balancing act! The "waterous" plants require higher rates than the other plants. In my case plants like cabbage,bak choy, lettuce, and cucumber flourish with generous amounts of water, while the others like bitter melon, tomato, hot pepper and celery require less water or they run the risk of developing root rot. This learning curve here taught me it's best to have separate beds for different types of crop, so that i can have more control with adjusting flow rates. A good idea, for everyone's benefit is to develop a low-medium-high(flow rate) general list of plants and their corresponding water requirements.

[TCLynx]

The original poster mentioned the pH was 6 and that lettuce also not doing well.

Ken, what sort of pH tester are you using and are you sure the pH is actually 6 and not lower? Since you can't measure ammonia or nitrate either I'm a little worried that the problem might be more than just the corn not liking your set up.

If the pH has dropped way below 6 (many of the aquarium test kits down measure below 6 so if it reads 6 is might be way lower) the bacteria could have crashed and it is possible you could be experiencing acidic water, high ammonia spike and little/no nitrate. Since corn is a greedy plant that actually likes a higher pH than many others, it might be suffering the most. Lettuce also does well with a higher pH.

[Ken Richardson]

I actually got a tester yesterday and the story unfolds. Ph actually 5.5, Nitrate 200 danger zone, nitrite said safe (can this be?), hardness 1000 very hard, alkalinity low, I am going to do a 50% water change, get rid of a few fish and see if I can find some seaweed extract around here. I will look for some water that doesnt have city cloride, additives in it. I decided that when the green beans took a beating and flowering peppers, squash flowers started dieing then it was time to find out why.

[Ken Richardson]

The fish have been active as always and dont seem to be having problems yet. Do you know how this will affect worms in the system?

[TCLynx]

What sort of test kit are you using? (some of the dip strips are pretty inaccurate)

I wouldn't worry too much about high nitrates in the short term (aquaculture often runs really high nitrates) but it will help to know what all the levels are.
Mainly
Ammonia
Nitrite
Nitrate
pH
Temp

If you can't find any Maxicrop or other seaweed extract, don't worry too much about that just now, some of your other issues are more pressing. If you do add any seaweed extract, make sure it is very low in nitrogen, like N-P-K values of 0.5-0-1 is what the Maxicrop original is. When I couldn't find any maxicrop, I used some Potassium Chloride (murate of potash) in small amounts early on.

Anyway, do you know what your city water has Chlorine or Chloramine? Chlorine can be easily out gassed with a bubbler and a few days sitting. Chloramine takes weeks to drop to minimal levels.

Good Luck

[TCLynx]

Worms don't like it too acidic but I would expect them to do fine in the pH range between 6 and 8 (so long as you don't make drastic changes too quickly.) They definitely thrive at a pH of 7.2 in my big system lately.

[Ken Richardson]

Looking at a C of more like 32 right now this is Arizona and still hot, but getting down to about 27 at night. I dont think the ph will be that high, more like 6.5 i would think due to not over 7 at the tap. I added about 1/3 of tank (total 27 gal) of water and poured it though my growbeds and I think that is what help start the problem, a couple weeks ago. I really hate learning the hard way lol.

[Ken Richardson]

do you think i should do a 50% water change at this point? I am thinking about using filtered water or buy from walmart the water like that. I have a seashell in each of the beds, do you know how that would affect it too? I put them in for calcium.