Sounds like a plan.
I've dangled tomato roots in the area in excess of 20 minutes without seeing any wilting. But then they have a large root mass. if yours is small, I would think 5 minutes or so should be okay.

@ stevey_frac
I guess the time you have got depends on your setup, as in if you use some medium or have your roots fully immersed in water or dangeling in NFT.

You should choose early morning or late evening for your operation, that will give you a larger time frame and more safety for sure ;-)

In case you run in trouble (which may happen for some reason) you can simply switch a hose with tap water to your system and run to waste or to a reservoir. This "emergency technique" is sometimes used with NFT setups, in case of unexpected trouble or technical failure to save the crops.

Just a quick suggestion here: If you keep the oxygen level high in your nutrient, there's really no need to change it. I measure what's being taken up by the plants and merely resupply the amount used using fresh nutes at the proper pH and EC. Makes life a whole lot easier.

One other thing: Keep the light off your nutrients. If your system gets choked with algae, the real fun begins!

You have already suggested less frequent nutrient changes several times freemangreens...
I basically agree with you, especially if you put it against some recommendations to strictly change nutrients on a weekly basis.

BUT, the best strategy truly depends on the setup, reservoir size, the amount of nutrient evaporated or sweat by plants, the Ph fluctuations and ion exchange that depends again on plant sizes, growth and density. If you just use a small amount of nutrients for a small setup, it's actually not such a bad idea to simply and completely change it every 7-10 days. It really depends on.

Most of my systems do consume a lot (because of plant density and tropical temperatures) and quite an amount is evaporated as well. That is why I replace a huge amount of nutrients on a daily basis. It would be a waste to completely change it on the weekend on top of that. But then again I do replace it then and now completely, to eliminate possible toxins, residues, chemical precipitations etc.

I also fully agree with you when you suggest to make one's life easier with a more robust and simple strategy. I mean, people telling me that they check PH three times a day haven't probably understood what it is all about. You monitor PH for some time and get the plot. After that you put the instrument away and just repeat your nutrient and topping off strategy. You can always check on occasion, but if you are smart you can easily anticipate your fluctuations after a while. If you do like I use to do, replacing lots of nutrients on a daily- (or 2 day) basis, you automatically keep the PH in a certain range and there you go.

I changed my lettuce solution and the response was immediate explosive growth. This leads me to believe that the nutrient solution had become depleted and possibly isn't strong enough in the first place.

My pepper plants get done tonight. I have to figure out a better way of doing this though. Right now I prepare the new solution, get it pH balanced, and add the nutrient, then take the plants out, dump the old stuff out, and then dump the new stuff in.

Problem is those buckets have to weight 60 lbs, and they are very hard to lift.

In other news, my pepper plants have started going white at the tips, which is concerning to me. I think when i change the solution i'm going to increase the amount of nutrient I give them.

I'd like your help setting up the nutrient solution Lucas. If i give you the three values on the nutrient bottles i have, (there is an A, and B part) can you tell me what mix would work best for my lettuce and peppers? (and my tomatoes that will be hitting the system soon?)

my remedy to moving heavy nutrient tubs was to put drain plugs near the bottom of them. if the tub is on or too near the floor to let gravity get the nutrients out, simply attach an external pump to move the water where you want it.
What brand nutrients are you using? does the manufacturer have a website that will provide concentrations for you?

The nutrient solution is made by Dnf? I've never heard of them before, but the fellow at the hydroponics store recommended them for me, and urged me to try it so much, that he in fact gave them to me.

Here is a link that might be useful: Nutrients I Use

I guess I can help you with that steve if you tell me what you have got. I mean have you both at you disposal, Bloom and Grow?

I can give you the formula how to calculate actual content out of the products data- and I can give you recommendations for lettuce, peppers and tomatoes formulas. From that you can figure out your own mix - actually combine and compare until you get something that suits. Although there are limits due to the composition of the product itself, you should get close enough. Is that what you meant?

That would be ideal Lucas,

At the moment I have only the grow A&B. I will get the bloom once I have anything anywhere near the bloom phase. Or at least that is my intention.

The recommendation that they give is 5ml / l of both A & B. But they only list that one value for all plants. My lettuce right now is getting about 2ml/l since i'm told they are light feeders, and my tomato and pepper plants are getting the full 5ml/l.

Steve, using only Grow limits you very much. The recommendation to use A and B always 1/1 is right, because both contain different elements in the right proportion when mixed 1/1. B for example contains the Magnesium and as soon as you use notably less of B (in relation or in total is the same), you may end up with a lack of Mg. A should contain the Iron and the calcium ( N of course) and the same role applies here.

I don't expect everyone to agree with me here, but I don't believe in very distinct formulas for grow/bloom. Some plants do indeed need ant take up more Potassium and somewhat less Nitrogen during flowering stage, but the differences aren't that big. Look, the flowering stage is actually very short and is followed by fruiting, and alternated by flowering/fruiting over some time. In fact many plants simply need more nutrients as soon as they start reproduction. As for tomatoes and peppers it is important to have enough Potassium in the formula all the way long.

I'd recommend to get that Bloom straight away to figure out a more appropriate pepper and tomato formula.

As for your nutrient concentration for lettuce: supposing you haven't got any EC-meter, you should ask the manufacturer what 2ml/L respectively 3 or 4 (of A and B) are supposed to give in mS/cm (EC). Your 2ml/L as in less than half strength might indeed be a bit week. Lettuce is sometimes grown between 0.9 and 1.2 but in some cases (under low UV) as high as 1.6 mS/cm (EC) and above. I guess you have to figure out what concentration gives best results. You should do so by a little more experimental-, yet safe strategy as long as you stay inside these limits. ;-)

Cheers
Lucas

Hey Stevey,I have some DNF at home. shoot me an email(see my profile page)and I'll email you the spread sheet I set up for calculating the various elemental concentrations.