EC questions

[crusher152]

EDIT: I will make it alot shorter ...

If the runoff water of a pot is 1.5 and I put in water with also 1.5 will the EC stay the same or will it raise ? Or will it only raise if there is salt buildup ?

 

[go4snypr]

not sure I fully understand your question.......If he is watering with tap water and the EC going in is 1.5, then it is stuff out of the water that built up in the mix. That is why the EC was at 2.4. Your better off with RO water (EC near 0) as it has nothing in it, and give you lots of room for nutrients. An EC of 1.5 means your water is already full, there is "no room" in the water to add nutrients.There is but you dont know whats already in your water.
I run about 1.0 EC in veg, which means if my starting EC is 1.5, I have no room to add my 1.0 EC of nutrients. If I use RO water, its near 0 EC, which gives me lots of room for nutes and then I know whats in it as well.

 

[crusher152]

Thanks for the answer but that wasnt really the question or I misunderstood you. The tap water is at 0.5-0.6 EC without anything in it.

It was just more of a theoretical question. If the runoff water is at 1.5 EC and I use water that also has 1.5 (with fertilizer), will the runoff water EC then raise or stay the same ? (without salt buildup).

Iam just tryin to understand if for example ppls say you need EC of 1.5 or 1.8, do they mean the runoff water or the water that Iam using to water the plants.

And for example if the EC of the runnoff water would be 0.8 and I want to have it at for example 1.5, do I need to water with 1.5 EC until the runoff water is also 1.5 or do I just water with 0.7 so it adds up ?

Sure I could just try and mess around but why stress the plants when someone knows this already.

Thanks in advance and sorry if I wasnt really clear on this. Hopefully I explained it now a little better what I mean.

 

[go4snypr]

When we talk EC, we are talking the water you are putting into your plant. If you feel the plant needs a flush, then you should flush until the water coming out is the same as the water going in. If you were in a recirculating hydro system then your "runoff" ppm would matter but as you are in a soil less grow all of your run off goes to waste so it doesn't matter.

 

[STOP]

if you are using 1,5 when watering NO it does not double. do a run off with your 1.5 and see what it is .that will give youself clue to what's happening..hope that helps you.

 

[crusher152]

When we talk EC, we are talking the water you are putting into your plant. If you feel the plant needs a flush, then you should flush until the water coming out is the same as the water going in. If you were in a recirculating hydro system then your "runoff" ppm would matter but as you are in a soil less grow all of your run off goes to waste so it doesn't matter.

Now this was finally the answer I was looking for, thanks alot.

And yes I had to flush because the runoff was at 2.4, i flushed without nutes but with PHd water until it was at 1.5. Needed about double the size of the pot in water.

Today the plants look much better, they even grew again finally. Because they stopped to grow nearly for a week :/ but now its good again.

I firstly thought they need fertilizer but good that I first checked the PH and EC. PH btw. always goes in at 6 and also came out at 6 so thats good but EC was a mess.

 

[STOP]

thats great that your plants are looking good. happydays

 

[STOP]

you should start a grow journal with pics and all.

 

[go4snypr]

Just to clarifly this.... we measure the EC so we know how much nutrients we have added to the water that we are feeding to the plant. I use Reverse Osmossis Water. the starting EC is near 0, (the ppm is about 30). I add nutrients to my water until i get to about 1.0 EC, (which on my meter is about 700 ppm, and this will change based on your meter calibration). I then water my plants. As I am in a hydro grow, my ph is kept right around 5.8, so that the plant can take up the available nutrients. The plant will only use what it needs though. As you are in a soil type grow, what ever the plant does not use, will stay in your soil. As these nutrients stay in the soil, you will get buildups. this can be corrected with a flush. Flush the soil mix with ph adjusted water with no nutrients in it. This will wash out all the build-ups without wasting nutrients as this water is just going to waste. Then water it with a nutrient solution at half strength.

 

[crusher152]

Hmm I always thought if you only use RO water that you cant keep the PH stable because there is no buffer ? Iam confused now about this. Dont ppls always mix normal tap water with RO water so they have a buffer ? Maybe I misunderstood here something or are you adding something so the PH stays stable ?

 

[go4snypr]

once you add anything to your RO water it is no longer RO water. I have never read anything about mixing it with tap water to make the ph stable... I will look into that though. but my opinion is that adding nutrients is the same as adding tap water, its just that I know what is in it, where as I dont know what is in my tap water. My RO water starts at about 6.5-7.0 after I add nutrients it lowers it to 5.3-5.5, if I let it sit it will climb to right around the 5.8-6.0 which is where i want it. But I do have to keep an eye on the ph as I recirculate my water in flower, and as water evaporates and nutrients and water is take up by the plant my ph does drift.

 

[crusher152]

Well you have a good point about knowing whats in, much better for sure. Maybe next time I will try out a RO system but I really went already way overboard with my budget. And after the flush everything is good again so at least for now I will continue this way. But I will keep the RO system in mind and do some more research for next time.

 

[crusher152]

Today a few days later the plants have yellow//burnt tips on new top leaves and here and there, its only the tips and very lightly but Iam wondering why. There are also a few leaves curling down, I just flushed with PHd water until it was at 1.5.

Maybe 1.5 is still a little too much for them ? I didnt use any fertilizer for flushing or after it. So I think I maybe should cut it down to ~1.2 tomorow, what do you think ?

Here is another weird thing, I have 3 plants that I flushed but the 3rd one is very small. The "big" ones are ~33cm and the small one maybe 1/3 of that size. After the flush the small one had an EC of 0.8 so I added veg fertilizer from Canna to bring it up (forgot to which EC lvl, now I write everything down ... not sure if it was 1.5 or 1.2, I think 1.2 but I forgot :/) and that plant doesnt have this problem.

Sorry that I cant post any pics at the moment . But besides that the plants look pretty healthy.

What kind of EC do you recommend anyways in veg stage ? I thought its 1.5 ?

 

[go4snypr]

I run 1.0,. on my meter that is 700 ppm using RO water starting at 30ppm and I add nutrients to 700ppm. depending on how the leaves are curling, if it looks like its "clawing", and the tips are burnt, I would say you are over feeding them. The "clawing" is nitrogen toxicity... not 100% without pics though. Also, how are you raising your EC without nutrients?? you said the tap water is .5-.6, and you watered with 1.5, if you did not add nutrients, how did you up the EC??

 

[crusher152]

EDIT: They looked better today, no brown tips .. they were just yellow, only 1 brown tip.

I repot them today because roots were coming out at bottom and then tested EC again and it was 3.6.

What does this now mean ?

a.) measuring after repoting is useless because the soil has fertilizer in it
b.) i mistunderstand something
c.) the soil has really too much fertilizer in it

I flushed them like I did with the small plant until it was at around 0.7 and then refeed it until it was at 1.0 (wanted 1.2 but the water was already at 1.6 and it only went slowly up so I thought better too less than too much).

I really had problems with the soiless mix from Canna since I repot my plants into them, always over fertilizing signs. I ordered now Plagron light mix with just little nutrients in it for my next plants.

And with the EC I thought I understood it by now but after the repot I dont know anymore :/, I really need some explanation now on this.

 

[go4snypr]

I think you are too worried about the run off ec. Set your EC in your feed water to a level you are comfortable with. Only feed every second or third time you water. This will make the plant use what is stored in the soil less mix and still give you a good feeding schedule. Then you only need to worry about a flush if the plant is showing problems. Unless it starts looking under fed, then you can add more fertilizer. Unless you are re-using the run off, I would forget about the run off ec. It will change based on what the plant is using and even though you can measure the EC, you still dont know what the plant is using or not using based on that reading..

 

[crusher152]

Thanks for your reply, yes you are right but its annoying when you dont fertilize at all and your plants always showing signs of it. For the next time i ordered me a light mix soil from plagron where you only have little fertilizer in it, will use it for veg grow. Because adding fertilizer if you see signs of deficiency is easy but to fight always with over fertilized soil can be real annoying as hell.

Not saying that the soil is overall bad but either I should have a RO system with it or only use it for the bloom period.

Thanks I really appreciated your answer.