What's new
  • Please note members who been with us for more than 10 years have been upgraded to "Veteran" status and will receive exclusive benefits. If you wish to find out more about this or support IcMag and get same benefits, check this thread here.
  • Important notice: ICMag's T.O.U. has been updated. Please review it here. For your convenience, it is also available in the main forum menu, under 'Quick Links"!

Measuring chlorine in dwc

Fatcrybaby

New member
Hi all,
I have a rdwc system and have delt with pythium for a while now and ive started using hth pool shock to treat my system with moderate success.
I use well water that is than run though an ro filter. So no chlorine from the tap.
I hear the optimal chlorine levels is 2-5 ppm. Im waiting on a hanna chloromerter, should be here in a couple days so for now im just using basic chlorine strips and i cant get a reading at all.
My system is about 1000L and the hth is 45% chlorine so at 2.25g/L i should be putting in 1 ppm of chlorine
If 1mg/L =1ppm

so 6.75 g should get me 3ppm
Ive put in over 8 grams and im stills coming back with a clear strip( no chlorine found)

Would these strips have trouble reacting in the presence of my nutrients?

Does hypochlorite break down as it kills pathogens? And it isn't present because its killing so much shit on its way back to the lead bucket?

Could excessive aeration help the chlorine escape? I have 2 very large air pumps putting lots of bubbles in the root zone.

Any advice would be appreciated, thanks
 

Mikell

Dipshit Know-Nothing
ICMag Donor
Veteran
Aeration does speed up dissipation, hence the need to actively monitor.

Maybe it's just a typo, but 45% of 6.75g/L is over 3000ppm.
 

Fatcrybaby

New member
Aeration does speed up dissipation, hence the need to actively monitor.

Maybe it's just a typo, but 45% of 6.75g/L is over 3000ppm.

Just in the chlorine solution, my system is about 1000 L so 3ppm in the system

Yeah, i was testing the lead bucket about every 10 minutes and still coming up blank each time
 

Mikell

Dipshit Know-Nothing
ICMag Donor
Veteran
No worries, one of the advantages of posting on forums is different perspectives. And occasionally someone points out the overlooked obvious. We've all been there.

Can't think of much else other than that the Cl is fully oxidized during the passage, but one would think with enough time/mixed solution passing through you'd be getting read back on the return.

Here's a free post bump ;)
 

Fatcrybaby

New member
Thanks,
Yeah the chlorine is spending much time in there, i have a big circulation pump that cycles through all the solution in about 10 min
 

D350

Member
Hi all,
I have a rdwc system and have delt with pythium for a while now and ive started using hth pool shock to treat my system with moderate success.
I use well water that is than run though an ro filter. So no chlorine from the tap.
I hear the optimal chlorine levels is 2-5 ppm. Im waiting on a hanna chloromerter, should be here in a couple days so for now im just using basic chlorine strips and i cant get a reading at all.
My system is about 1000L and the hth is 45% chlorine so at 2.25g/L i should be putting in 1 ppm of chlorine
If 1mg/L =1ppm

so 6.75 g should get me 3ppm
Ive put in over 8 grams and im stills coming back with a clear strip( no chlorine found)

Would these strips have trouble reacting in the presence of my nutrients?

Does hypochlorite break down as it kills pathogens? And it isn't present because its killing so much shit on its way back to the lead bucket?

Could excessive aeration help the chlorine escape? I have 2 very large air pumps putting lots of bubbles in the root zone.

Any advice would be appreciated, thanks

I have also problems with root rot, bacterial tea is not working anymore....
Next round I'll go with pool shock, the same as you.
Some advice (still new in this, use with caution):

-Do not use chlorine meter. you dont care how much chlorine you have, you care how much FREE chlorine you have. Use ORP meter for that! 750mV is about 1ppm at ph 6

-Buy an ORP controller, it is the only way to maintain constant leves.(Ebay) Free chlorine dissipates VERY quickly, either with bubbling or reacting with organic crap you have in res.

- I have tried to add Chlorine in the res and measured ORP/redox potential - guess what, I added 10x the amount of chlorine as calculated and still got NOTHING after 20min. Initially you will have to put a lot inside reservoir. Later not so much.

Let me know, how it went...
 

MD84

Active member
very interesting thread. Anyone have any updates or anymore useful info to share? I'm about to start another grow with some calcium hypochlorite and was going to get a chlorine meter. Would be interesting to know how others got on first though...
 

Hydro8

Member
A couple of times I have had funk in my system(usually from rockwol clones and soil on clones) a couple of things I have done and noticed. I don't use any thing more then PH and PPM pens for testing, I just use smell and look/clarity. So based on that..

I use tap water that smells like Chlorine I aerate it for a couple of hours and the Chlorine smell is gone. When I had funk I would not air out the Chlorine from the tap water I would just mix my nutes in with it. I figured it would aerate out of the system with in 12-24 hours(longer then an open tub because less air exposure. I figure tap water has free anti funk/bacterial stuff why not use it.

From what I have read here and there chlorine is gone from an aerated system within 12-24 hours with 90% of it gone in a few hours.

After 24 hours of chlorine water in my res I will watch the nutes for cloudy appearance and funky smell. In bad cases it the funk would start return in 48-72hours. Then I would but bleach(household 6%) .25ml per gallon in the res, that has always killed the funk at the lighter beginning stage. With Bleach I feel like it gets aerated out of the system about the same as Chlorine. I am careful to not add more for at least 48-72 hours.

Like I said this is all based on my hobby experience I would love to hear more about it from a professional or someone with a professional grade chlorine tester.
 

D350

Member
very interesting thread. Anyone have any updates or anymore useful info to share? I'm about to start another grow with some calcium hypochlorite and was going to get a chlorine meter. Would be interesting to know how others got on first though...

After years of battling with root rot, I can say, calcium hypochlorite saved me.
Just add daily, use orp meter, thats it.
normally I add to about 600-700mV and leave it after night. Next day should be 300-400mV. If it is less, you have crap in the system.

Any more info let me know.
 
Top