That looks like a fungus decomposing your starter cube, so yeah, it's probably the mycorrhizae.
If you're using GH Flora series nutrients, you don't need the mycorrhizae as the nutrients are already available. With what you're feeding the plants I would suspect they're growing new leaves like crazy. Any algae growing? My guess is between the fungi, the plant, and any algae that may be growing, they're really eating up the nitrogen pretty quickly causing the pH to swing upward.

To remove the fungus on the cube you can squirt some 3% hydrogen peroxide on it. I have done this many times in the past and it always gets rid of most of the algae/fungus on the cubes.

Thanks for the solution to remove fungus on the cube by nutrient.
My friend use an advanced nutrients product for hydroponic system and really its workable.

Here are my cucumbers just in case anyone has any interest...

I don't see any algae in the containers and after only a couple days I'm not sure that i would see the algae yet. I am currently running the water collection for my RO system to do the first nutrient change out tonight.

I am using the maxi series and not the flora series so I added the fungi/bacterial mix since it was recommended by worm's way. I do believe that is why the starter plugs are white it must be the fungi/bacteria and doesn't seem to be harming the plants any.

The ph swing is killing me. The ppms are around 800-1200 depending on bucket and that hasnt really fluctuated in the two weeks. The ph has gone crazy though. I am thinking that the plants have been locking nutrients out or id have seen a drop in ppm right?

My tomato plants especially seem to be curling their leaves especially around sundown. It makes me wonder if maybe its because the ph is swinging outside their range for nutrient uptake.

Just to make sure this is the procedure i have been using . Maybe I've been doing something wrong.
1), Fill 20g container with RO water.
2), Add 20 teaspoons of both maxical and maxigrow
3), Add 1 teaspoon of fungi/bacteria
4), stir and place bubblers in the solution
5), After sitting for 5-10 minutes i take a ppm and ph reading
6), If ph reading is too low (that is normally the case) I add ph up
7), I stir the solution and let it bubble away for 5-10 minutes
8), Once the solution is around 5.5 to 5.8 I siphon the solution into 5g buckets and place the bubbler and plants into the buckets and place them under the lights.

Any advice is welcome.

Thanks

a pH swing from 5.5 to 6.5 (even 7.0) isn't going to dramatically affect a tomato's growth. If the water always stays in that range you really have nothing to worry about.
Since your nutrients are not really plant ready (they need to be decomposed by the fungi) that probably has a lot to do with pH swings. I'm not really a proponent of growing fungi or bacteria to grow a plant with but my understanding is pH is not as much an issue. But I could be wrong.

The nutrients are not plant ready? I did not realize that maxigrow/maxibloom needed to have fungi in order to be plant ready. I just added the fungi thinking it may thwart bad bacteria/fungi.

Oh, my apologies.
I thought you added the fungi because you had to. I've never used the maxigrow series. a properly maintained system will not normally have issues with bad bacteria or fungi.

Maybe i should not add it during the current nutrient swap and see if that keeps the ph more normalized...

So I changed it up a little this time to see if it made a difference. I did the following:

1), Fill 20g container with RO water (about 18gal)
2), Add 12 teaspoons of both maxical and maxigrow
3), Mixed the solution and waited 5 minutes or so
4), The ppms were close to 1300 and the ph was 4.5
5), I read that i should not use ph up or down if i could help it so i added 25 glasses of tap water and mixed
6), The solution was now at 1000 ppms and ph of 5.5 I placed the plants in the buckets and placed them under the lights.

Not using the fungi/bacteria def made it easier to bring the ph in range. Will my tap water affect the plants much if i mixed maybe 2 gallons to 20? My tap is 200 ppm and ph of about 8.

So it has been less than 72 hours and the ph has already gone up to 7.2

It has been cloudy and relatively cool outside so the inside temp has been 75 degrees the entire time.

So far all that has been introduced is maxigro and maxical. What would cause the ph to swing from 5.5 to 7.2 in two days?

It is probably your tap water. try filling your container with RO water and adjust THAT to a pH of 7.0. (use pH up if need be) and let that sit for a few days then check the pH. If it hasn't changed, add your nutrient concentrate and record the pH. The let THAT sit for a few days and see if the pH changes. If it does not, add tap water to get the pH to where you want it. Let THAT sit a few days and see what happens to the pH.
Follow that procedure and you'll likely know the culprit.

This swing happened before too without any tap water though only RO... I will fill a jug with ro water and another jug with tap and do the test but something tells me it is outside the realm of the water. Maybe a buffer of some sort in the nutes/cal/mag . Or maybe the water being in contact with the hydroton is changing the ph (even though I rinsed the hydroton like 3 times).

yes, I agree with your thoughts about hydroton. When I first dabbled in hydro the hydroton gave me pH swings too. After a few seasons it hasn't been an issue though. Maybe next time try soaking the hydroton in pH corrected water like you would with your rockwool cubes.

Yes that is a good idea. I may try soaking it next. Heres an update though. the ph of the test jug last night was 5.5. This morning it was 6.5.

No hdroton, no plants. Just nutes water and ph up/down

Now what?

Test just your RO water. if it changes, you may have something wrong with the system. BTW, 8.5 isn't bad. why not leave the just for another day then check the pH again.

So funny thing happened :D I got some PH 7 to re-calibrate my PH meter. Seems it was off by 1.2 PH. I'm not sure when it was thrown off so it's hard to say if the PH was actually swinging or not.

So I have noticed some possible nutrient burn (yellow and brown around leaf edges) also the older leafs on some of the plants turned yellow or brown and fell off. Could this be because of nutrient burn? Seems that an excess of salts/nutrients would show on starter plugs too right?

To be honest I thought this was going to be much easier. I guess I don't have a very green thumb. I sure hope I can figure this stuff out as I can see how this would be an extremely rewarding hobby.

So I feel like such a newb... Every couple days its something else... I am including a pic of what is happening. About a day after i did the nutrient change my Cucumbers which i had thought looked pretty good did this weird drooping of the leaves. I didn't know what was wrong so i didn't do anything two hours later they seemed fine. A couple days after this episode I started to get spots on the leaves. I'm really hoping its nothing bad...

Here is a picture of when they went real droopy like. The one plant even tipped over.

Too much nutrients. I suggest removing half of you nutrient solution and replacing it with water. Let the plant rebound. Your last post is a couple days old so I dk if your plants are still looking like this or not. Hope this helps

I should also mention that this frequently happens to me with my cucumbers outside. This happens when the temperature is high (90+), when nutrients are near ~2.0 EC, and generally when I let the reservoir almost go empty before adding more water/nutrients.

This post was edited by ethnobotany on Thu, Feb 21, 13 at 14:42

Ya After pinching off the affected leaves (not sure that was smart) I found that the water levels had dropped about 3 inches per bucket leaving only a couple roots in the solution. I added RO water to it Yesterday morning hoping everything will turn out just right...

Thanks for the reply

Not enough water and too high nutrients, even too high of temperature can also cause wilting of leaves as you have seen. You will find out that even an experienced gardener can have these issues. Don't be turned away because of this. An experienced gardener may not be able to avoid these issues, but shows his/her experience by how you deal with the issue.

Cucumbers use a lot of water, especially when they get bigger and produce fruit. You're gunna need at least an entire 5 gallon bucket per plant to be able to keep up with the water levels, otherwise you will almost certainly run into problems. If you could rig 2-5 gallon buckets per cucumber, using one as an external reservoir, that would be even better.

Keep it up. The learning curve is pretty quick with hydro!

I will definitely heed the warning about the water. I have 2 plants and 2 buckets. I have also just freed up an 18 gal container as my lettuce completely failed. ( I think the temp swings from 50 to 80 destroyed it). May i should place the cucumbers in the 18 gal tub instead of the buckets.

I also started to notice flower buds. That is pretty exciting although isn't 16 inches too small to start flowering as this cucumber variety is supposed to be fairly tall?

So I got two flowers that bloomed but the next day closed up. I believed them to be male flowers and definitely thought they were supposed to stay open for a little while longer. Should i move to the bloom nutes now? Its been 30 days and the seed packages say 60 to maturity.

Looking at the last pictures of the plants they look a little small. Personally I would wait till they get a little bigger before adding the flowering schedule of nutrients, but that isn't to say you couldn't start giving them flowering nutrients now if you wanted. Its really personal preference since the plants will still keep getting bigger even with the flowering nutrients. Also, since the 18 gallon tub is available I would stick the plants in there.

Ethnobotany:

Thanks for you replies. The only reason I was thinking of switching is that I am unsure what happens after these male flowers bloom and drop off as they have started doing (4 flowers now in 2 days). I thought that maybe the bloom formula would stop the flowers from dropping so quickly.

I have also noticed that most of my plants have stopped growing. I found that quite odd considering how much they were growing before. I will move the plants to the 18 gal tomorrow. I hope to keep the cucumbers in veg longer but really am worried about the flowers closing so quickly.

The good news is that everything is green and looks overall quite good.

Thanks again for your help

Not a problem! Hopefully you end up with some nice cucumbers.

And don't worry, often times the first blooms are going to drop off anyways whether its tomatoes, cucumbers, whatever.

So I think one of my Tomato plants has curly top... Its really weird to me that i would get it indoors in a hydro setup as i haven't seen any bugs at all... I will post a pic in a couple hours so everyone can see.

excess nitrogen can cause new tomato leaves to curl.

Pic one

pic 2

If your ppms are actually in excess of 100ppm, cut them back. The extremely dark green and curling make me think too much nitrogen. It shouldn't hurt the plant but if you don't like how it looks try a ppm in the range of 700-800.