Evaporating water and tds

[greenhornets]

Hi everyone. I am running a small ebb n flow system with a 20 gallon reservoir. I think the water is evaporating because the water level is going down but the tds stays the same .the only time the the tds changes (goes down ) is when i back fill the resivor withe distilled water . why wont the tds go down naturally ( meaning the plants using up the nutrient). i change out the the water weekly and only running a tds of 600 . i added 1.5 gallon today and it dropped to 570/580 . the plants are vegging and i was waiting for the plants to start using the nutrients before i started to raise the tds any higher.
a little back ground on the clones, they had root rot and i managed to clear that up . i think . i say this (cured the problem) bc i transfered the clones to the ebb n flo i noticed the root had turned white again and had some more roots when i was putting then in the pots with hydrton pellets ( b4 they where brown and slimy). the tds has been staying the same for the last 2 weeks . the tds doesnt go down and it doesnt go up. the only time it changes is when i back fill with plain distilled water . can anyone help me solve this problem . please . thank you any help would be greatly appreciate.( ps . welling to dance at your wedding or funeral witch ever came first).

 

[10k]

Can anyone help you solve "what" problem ?
Right now, at the stage of growth your plants are currently at, your res topping and changing is sitting right on the mark for what the plants are uptaking based on your res top off res changing strategy.

But lets talk a bit more about res strength topping and res changing strategies...

To me it sounds like you've got it fairly well "dialed in" for your plants existing size running at 600 ppm, but as they grow larger you may find they're looking for a stronger res. I'd change up your topping and res changing strategy a bit by topping off every other time with about half the starting res strength, but keep in mind as the put on more foliage they may desire more food. Plus you can go two weeks between res changes with no problems, right now at once a week you're throwing away viable nutes.

For now I'd try running the res strength up some, by topping it off with a 400ppm mix alternating top offs with straight water. This strategy should raise your existing 600ppm res strengths up somewhat, and if your plants don't show any adverse effects of the higher strengths you should be able to bump it up to a res starting strength of about 800 ppm through the next two week res life, and subsequently going stronger shooting for a 1000ppm res as those plants begin exploding with growth.

Once vegging plants have adequate foliage/size, I've always strived for running the nute strenght up to the point of the plants beginning to show a very slight tip burn (known as a greenhouse burn), then backing it off just slightly to find their hunger level. It's good to allow the pH to drift around the range a bit too, starting with a pH of about 5.7 and drifting up to about 6.3'ish

Surely though, there IS "more than one way to skin a cat"...
I am quite sure this thread will expand with other strategies people use for reservoir maintenance.
Some folks never ever change their res at all but just add in more mix to a given target strength.
I however am a firm believer that the plants will take what they want and need, leaving whats left behind in the res mix lacking some elements and somewhat toxic in other element levels. It is my belief that res maintenance can only go so long before the res needs a complete fresh change out.

discussion ?

 

[greenhornets]

10k, man for the help . i thought i had a problem because the ppm wherent rising or falling. im a FNG( fucken new guy )and only know enough to get me in trouble. Could you explain alittle more on the tds numbers please .
... (For now I'd try running the res strength up some, by topping it off with a 400ppm mix alternating top offs with straight water. This strategy should raise your existing 600ppm res strengths up somewhat, and if your plants don't show any adverse effects of the higher strengths you should be able to bump it up to a res starting strength of about 800 ppm through the next two week res life, and subsequently going stronger shooting for a 1000ppm res as those plants begin exploding with growth.)...
...... could you explain this alittle more bc im using tap water . straight from the tap the ppms is 220. i then let it sit over night and it drops to 170/180 . Should i still shoot for a tds of 400 on every other topping off with my starting ppm of 170/180 or a little higher tds on this res cycle ?
...... On the next resivor change you said bring the ppm up to 800 ppm and steadly bringing up the tds to 1000 tds when topping off and backing off when plants tips start to show signs of nutrient burn .( should the top off water be 400 tds or what ever it needs to be, to steadly bring the tds up to 1000 over the next 2 week cycle??
also im using pbp nutrients and cal-mag/ should i be using both product to bring the tds up to 400 or a 400 tds with the nutrients alone and use cal-mag as bottle direction. im changing nutrients out this week end and will be going by your directions . Thanks Again!!
Man im sorry for asking all this question but, im just trying to learn.
......Thanks again....

 

[icough2getoff]

How do your plants look? I haven't grown in ebb n flow for very long but when I used to grow in DWC my plants always looked healthiest when the ppm stayed the same as the water level drops. This old OG FAQ has been very helpful for me in the past.

 

[greenhornets]

Hey Icough2getoff. I guess they look ok. I think they have recovered from root rot from when i had them in cloner. This is about three weeks in the ebbnflow. Any comments or suggestions?