Adjust PPM With Ebb & Flow With Waterloss?

Hey guys. I've been concerned about this issue for a few days and I haven't really been able to find any info on the net about it. For my first grow I built a really nice DIY ebb & flow hydroponic system using 2 Rubbermaid tubs some fittings with a pump and timer. Works like a charm and the plants love it but the system has a bit of water loss which makes the fine tuning of the PPM difficult.

I understand that if the ppm's rise you should lower the PPM's and if it declines you should add more nutes but what if the system looses around a gallon a week. Obviously the PPM's will rise as the reservoir increases in nute concentration.

I am currently growing 7 707 headband plants from fully rooted clones about 5 inches tall. They have been vegging for about 19 days and I am going to switch them to flower within the next few days.

Currently my PPM's are around 800 but they rise daily. I am using fox farm fertilizer and it is saying for week 3 they should be like 950.

What do you guys recommend I do to fine tune the ppm;s?

how many liter res are you running?

I just make up my res at the beginning of the week, with all appropriate nutes, then just attempt to keep the water at the same level everytime i check it. The better growers on here swear that less is more, so if it gets eaten up that week, no big deal, just change it as normal at the end of the week. I have read on dutch masters website about growers adding a 1/4 solution instead of straight water, but they also have you run really really high ppm (in aggressive setting). If your ppm has not dropped by 30% or so i do not see a whole lot of reason to adjust it.

I just checked my PPM's they were about 780.

I am running a 12 gallon reservoir. (45.42 liters).

I was thinking about marking the reservoir and adding pure RO water to it daily to bring the water levels up but of course that would continuously dilute the ppm levels. I figured a little waterloss is ok becqause it would graduly acclimiate them to higher and higher ppm levels but not if it rises by a large number daily.

The problem is that I am basically guessing at their desired PPM level. They did show minor signs of nute burn their first 2 weeks with just minor brown tips of their leaves but the new growth is totally fine with no signs of burns.

I took these photos yesterday which is their 18th day in my cabinet. They were fully rooted 5" tall clones when I got them.



Minor nute burn:

I don't think that's nute burn--It looks like the heat from the bulbs.

Interesting. Like I said this is my first grow so I'm learning daily.

The brown tips are only on the older leaves the light is a lot closer to the new growth without any browning.

Looks like you have algae in your table, is there standing water in there? If it is you are gonna have a real big problem real soon.

choempi said:

Looks like you have algae in your table, is there standing water in there? If it is you are gonna have a real big problem real soon.

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Yah there is a bit of algea in there . Yah there us a small layer if water about an 8th inch usually dries pretty quick. The table ... Isn't a table so it doesn't drain entirely like an actual flood table

blackonblack said:

Yah there is a bit of algea in there . Yah there us a small layer if water about an 8th inch usually dries pretty quick. The table ... Isn't a table so it doesn't drain entirely like an actual flood table

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That is going to become a very serious issue. You are gonna need to clean that, and come up with a fix. Algae is also on the rockwool, that is easy to fix. Use some plastic or mylar or cardboard or tinfoil, anything to cover the tops of your pots. The algae will die without light.

If you want some ideas on fixing your table issues, I have ideas, but also others will.

Believe me when I say you can not ignore. You will begin to smell a problem too and your plants are gonna suffer. Maybe die.

Hydro can not co-exist with algae.

listen if your ppms are going down that is a sign the the plants are taking in the nutrients and thats a good thing. If the water level is going down and ppms are going up they are drinking more water then taking nutrients.

choempi said:

That is going to become a very serious issue. You are gonna need to clean that, and come up with a fix. Algae is also on the rockwool, that is easy to fix. Use some plastic or mylar or cardboard or tinfoil, anything to cover the tops of your pots. The algae will die without light.

If you want some ideas on fixing your table issues, I have ideas, but also others will.

Believe me when I say you can not ignore. You will begin to smell a problem too and your plants are gonna suffer. Maybe die.

Hydro can not co-exist with algae.

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Clear as a bell. I know I need to get that risidual water out if there. I was thinking about drilling a small hole which would just slowly drain the left over water but won't effect the flood because my pump is powerful. I have the pots out of the water but the roots are starting to sit in sone stagnant water.

kingme said:

listen if your ppms are going down that is a sign the the plants are taking in the nutrients and thats a good thing. If the water level is going down and ppms are going up they are drinking more water then taking nutrients.

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I understand but my system is loosing water due to hydro fluid evaporation from the tray that doesn't drain completely.

blackonblack said:

Clear as a bell. I know I need to get that risidual water out if there. I was thinking about drilling a small hole which would just slowly drain the left over water but won't effect the flood because my pump is powerful. I have the pots out of the water but the roots are starting to sit in sone stagnant water.

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Every time you flood, the algae grows, even though you think it dries up-it does not die. It is a perfect environment for it to grow and thrive.

The crux is light+water= algae.

Your drain idea is good. You could figure a way to cover the top of the tray somehow since I see the sides are higher than the tops of your pots. You could put in a few inches of hyroton, or gravel, so the bit of water that does not drain is not in direct light.

First, take out your plants and scrub out the tray with soap water and bleach. Then do what ever you decide when you put the pots back in. Are you using organic nutes?

I built my own and went through this too. If you are not using organic nutes, I advise reading this thread Bleach instead of h2o2

choempi said:

Every time you flood, the algae grows, even though you think it dries up-it does not die. It is a perfect environment for it to grow and thrive.

The crux is light+water= algae.

Your drain idea is good. You could figure a way to cover the top of the tray somehow since I see the sides are higher than the tops of your pots. You could put in a few inches of hyroton, or gravel, so the bit of water that does not drain is not in direct light.

First, take out your plants and scrub out the tray with soap water and bleach. Then do what ever you decide when you put the pots back in. Are you using organic nutes?

I built my own and went through this too. If you are not using organic nutes, I advise reading this thread Bleach instead of h2o2

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I'm using fox farm nutes. Have there complete product line. There big bloom is organic.

I don't want to use hydroton on the bottom because I want to be able to move the plants if I have to. Is it really necessary to scrub it out or can I just cover it. Won't it die in a few days. My main concern is the stagnant water. I have the pots raised above the water but the roots are now basically partially submerged plus the water loss and algae problem.

blackonblack said:

I'm using fox farm nutes. Have there complete product line. There big bloom is organic.

I don't want to use hydroton on the bottom because I want to be able to move the plants if I have to. Is it really necessary to scrub it out or can I just cover it. Won't it die in a few days. My main concern is the stagnant water. I have the pots raised above the water but the roots are now basically partially submerged plus the water loss and algae problem.

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You can do what ever you want, but just warning you that every time you flood you are pushing algae into your root system and it will not go away easily, any light leak is all it takes to keep it growing. Root rot kills.

You will start seeing sludge and a smell like a swamp.

how do you deal with your algae. Are there any tips to make sure my tray completely drains?

blackonblack said:

how do you deal with your algae. Are there any tips to make sure my tray completely drains?

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I made mine out 58qt tubs that I cut the sides down to 7in, and had my fill and drain 1/2 tubing in the ends, Flood 3" up and the drain as close to the bottom as possible. I had the tubs tilted so they drained fairly well but had small bit of water left. I tried h2o2 for a while, then saw that it couldn't stop algae from growing. I did some research and found out that some peeps,very very few, used bleach to keep their systems clean. Of course many shriek at the thought of adding bleach when it has been pounded into us that you must let water stand 24 hours to let bleach dissipate!!!

So, I started using bleach, and worked like a charm, kills every damn thing in the water and roots white and plants healthy. Had a hard time finding how much to use and like I said, if you say anything against these old myths of growing, many peeps ragged on me saying I was killing my plants.

HA!

Lots of peeps say shit they have heard and don't really know, and they repeat each other like mindless sheep.

Put out a thread and Fatman explained the whys and told me how much.

Problem is you can not use bleach with organic nutes. I don't give a fuck about organics and think it is another thing peeps like to bleat about. Me I grow hydro weed not soil, so don't want or need live micros in my water. Works for me, but won't for you. Not meaning to slam you personally about organic nutes, just sometimes it is so much hype and nute companys feeding the masses lables.
My opinion.

Hi choempi,

Care to share the amount of Bleach used per Gallon? Would like to give it a try.

Thanks

Remileveu said:

Hi choempi,

Care to share the amount of Bleach used per Gallon? Would like to give it a try.

Thanks

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6 - 8 drops a gallon, then add back every 4 or 5 days. But can't be used with organic nutes!

Bleach instead of h2o2