Chlorine Friendly Nutrients In Canada

I have been a member for quiet some time now, but never had time to do much on here. Now I have time so thought I would try to get a problem solved that I have always had. The same problem as many... Root Rot. I have a RDWC system with a chiller. Water in the containers is between 63 and 65 degrees. The water is from a well and goes through a household water softener system, then a RO system, and from there through a UV system. Right now I am using H2O2. I buy 29% H2O2 and mix it with water from the above system at the rate of 1 part H2O2 and 9 parts water. I mix 2,250 parts water to 250 parts 29% H2O2. This gives approximately 3% H2O2. I use (what most people would say is too high) 8 ml per L. and every 24 hours add 30% of what was put in the reservoir minus the amount of nutes the plants would have used. for example... 100L nutes gets 800ml 3% H2O2. 24 hours later if the plants used 10L, then 90L nutes would get 720ml H2O2. So, I use 30% of 720ml, which is 216 ml of H2o2 for the make up H2O2. I know about the cleaning and sterilizing and so on, but the root rot always seams to show, yes , even with that much H2O2. All of the above to get down to this... I have read that many people on here have had good luck with pool shock and so I bought some. I got HTH Extra...available chlorine present as Calcium Hypochlorite is 75%. I mixed up a strong solution and added enough to my tank of water that brought the water to between 3 and 5 ppm free chlorine. my test strips measure from 0 to 10 ppm. One of the increments is 3 ppm to 5 ppm and the color of the strip falls in that area when the water is checked. I use Remo nutrients. The problem I have now is that it seams that something in the nutrients is reacting with the chlorine, because when the nutrients finish mixing the chlorine is gone. From start to finish 20 to 30 minutes. I have read that ammonia can cause this. Nothing on the bottles says anything about ammonia of any kind. So, I am willing to change to another good brand of food that chlorine will work with. Any information anyone can give me would be greatly appreciated. Sorry this is a bit long of a read.

if strong peroxide isn't helping, you have a serious problem somewhere in your system that's causing root rot. i'd try to figure out what it is.

Have you thought about putting a UV clarifier inline with your RDWC system?

I thought that to, rxymtnman, but for the life of me I can't figure it out. Temps should be ok and there is lots of air in the res as well as each container. No, never thought of doing that, xtsho, but then I had to look on Amazon to see what it was lol. The plants are showing a sign of root rot, nothing serious yet and I'm hoping the H2O2 will hold it at bay. I'm thinking that I will drop the temp a bit more. I'm thinking I could go down to as low as 60F without slowing growth. Xtsho, have you had experience with a UV Clarifier?

The Older Guy said:

I thought that to, rxymtnman, but for the life of me I can't figure it out. Temps should be ok and there is lots of air in the res as well as each container. No, never thought of doing that, xtsho, but then I had to look on Amazon to see what it was lol. The plants are showing a sign of root rot, nothing serious yet and I'm hoping the H2O2 will hold it at bay. I'm thinking that I will drop the temp a bit more. I'm thinking I could go down to as low as 60F without slowing growth. Xtsho, have you had experience with a UV Clarifier?

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I've used them in ponds And they work extremely well keeping the water crystal clear. I've never done RDWC just DWC and flood and drain but they are used in recirculating hydro systems to prevent root rot and other nasties. They sell them just for that purpose although the ones targeting hydro growers are more expensive than just using one for a pond.

The downside is that it degrades chelates causing them to precipitate out of solution. But that's going to depend on the nutrients your using. I notice you're using Remo nutrients and took a look at those and the micronutrients they use are all chelated. That may or not be an issue though and it could possibly be solved by adding some additional Micro when topping off between reservoir changes if it was a problem.

I wish I had a more experienced answer but I've never used one in practice for hydropincs but they are used. The chelate issue may not even be an issue. When I was doing hydro I just used plain old Chlorox bleach after my first bout with root rot and never had it again. Good luck on resolving your issue. There are numerous methods people use for treatment.

Also, are you positive you have root rot or could it be staining from your nutrients? Slimy is bad but just because they're not white doesn't mean it's root rot.



Interaction of UV light with Fe-chelates can be a problem in the disinfestation of nutrient solutions. However, under certain conditions, and depending on the Fe-chelate, plant growth may be significantly increased by the use of UV light for disinfestation of nutrient solutions [2].

The solution was either untreated or passed through a UV disinfestation unit at a flow rate of about 124 L⋅min–1. Within seven days of transplanting, all untreated spinach seedlings were dead whereas no plant death or root infection occurred in the plants grown in UV-treated water.

Benoit and Ceustermans [11] tested a UV unit with a 60-W central low-pressure mercury lamp to reduce the Pythium root rot infection in lettuce. At an average radiation of 98 mJ⋅cm–2, no lettuce plants were lost, even though the seedlings purchased for planting were found to be infected with Pythium sp. Laboratory and greenhouse experiments have also demonstrated that UV light eliminated spread of a single point infection of Fusarium oxysporum f. sp. radicis-lycopersici (FORL) in ebb and flow, and NFT systems [45].

Thank you Xstho for all the info. Like you, I had planned on using bleach/pool shock. I mixed the pool shock into the plain RO water until the test strip showed a ppm of free chlorine between 3 and 5 ppm. Next I mixed Remo nuts Grow, Micro, and Magnifical into the water. I tested the water with the nutes again and was quiet surprised to find the test strip showed no chlorine at all. This all took place in around 30 minutes. Maybe regular bleach would work better. It's a little different than pool shock. I expect a UV system would need water pumped through it full time. The containers that hold each plant holds around 23L each so I feed every 15 minutes. The pump I have is too big so it pumps more water than is needed and it takes a few minutes for the water to drain back to the res. The res it's self is 90 L . I think what I'm seeing is the start of root rot. Most of the roots look great... nice and white, but there is the odd spot that has a brownish look. I can't see all the roots. I can only look through an opening I cut in the top of the container and the plants are too big to lift out. I check every day with a LED light, so if it starts spreading I should be able to tell.

bacillus amyloliquefaciens

No chlorine or peroxide if you go this route.

I'm not familiar with the term bacillus amyloliquefaciens. Is it a good bacteria? I have used Hydroguard. I used it as directed, but still got root rot.

The Older Guy said:

I mixed the pool shock into the plain RO water

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you'd be better off and much more accurate if you weigh it out. 0.1 grams in 10 gallons of water is 1ppm. up to 5ppm is safe

The Older Guy said:

I have used Hydroguard. I used it as directed, but still got root rot

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if you are comfortable, put up pics of your operation. hydroguard and peroxide not working sounds to me like an un-fixed issue

I'll take pics and put them on. Have to admit, I'm not very good at this, but should be able to figure it out. What I did with the pool shock... I mixed 6 grams of pool shock into 3L of RO water. I then added the ml needed to bring my RO water to 3 to 5 ppm of chlorine using a test strip. That was easy. My problem is that after I added the nutes and tested to see if the ppm of chlorine had changed .... it did... a lot. The test strip showed no chlorine. I have read on here that some nutes can do that... Also, would like to say thank you for taking the time to go through this with me.

Stick with the peroxide. I've used 35% at up to 8ml/L when root rot was present and wiped it after a few daily doses. I've done a lot of DWC grows and always added 0.5ml/L of 35% twice weekly for maintenance.

Chlorine is a toxic chemical and a known carcinogen and as you've discovered can mess with your nutes or them mess with the chlorine so it doesn't work. Both will react with any organic material so use either with that in mind. H2O2 will attack dead material faster than live material as the dead stuff lacks oxygen so the radical O+ ion goes for that easier. The rest of the H2O2 becomes H2O and is totally non-toxic.

Don't dilute it beforehand either. Measure out what you need and add slowly while it circulates or the bubbles from an airstone mix it in. If you get any on your skin wash off immediately and don't worry about the white patches. That's just dead skin cells that reacted with the peroxide right away.

Wear good eye protection with either or any other nasty shit you may handle in the future. Chemical burns on the skin will heal but in the eyes, not so much.

Edit: I just checked your OP an see you have a chiller. I stopped using peroxide once I made a DIY chiller out of an old water cooler and fountain pump and could keep the nutes at 65 - 68F. Did another 15 - 20 tubs after that and never had any rot show up. Do you know what temp it is in the buckets where the roots reside?

I’m pretty sure salts can skew your chlorine readings
I’m curious are you using test strips for a pool or for drinking water?
I’m of the mind that you are letting light into your system somewhere
I never tested chlorine levels but relied on measuring by the gallon using unsoftened well water
Haven’t done hydro in ages but never had root rot except when a pump was overheating the rez

Thanks for the replies guys. Yes; I think you're right OldMedUser. I've pretty much decided to stay with the H2O2 and only use the chlorine between grows to clean everything. 8ml per L of 35% H2O2 seams pretty high. I use 8ml of 3% H2O2 and I thought that was high. Did your plants leaves droop some?

The company I buy from only carries 29% H2O2. I guess this is ok: just have to use a bit more. I was bringing it to 3% because the info I was able to find on mixing H2O2 into the res was always at 3% and said to use up to 3ml per L. That didn't do anything for me. Thinking that if 1 part 29% H2O2 to 9 parts water makes 3% H2O2 and I'm using 8ml per L of 3%, then I should be able to use almost 1 ml of 29% H2O2 to get the same strength. What's your thoughts?

I have been adding 30% of initial dosage of H2O2 each day for make up because of the root rot issue. I make allowances if the res is down and I add H2O2 to make up water at the rate of 8ml H2O2 per L . Most of the roots are good, but there is the odd spot that looks like root rot. I'm not able to lift the plants, so I am limited as to how much I can see. I am going to take pics of the system today and hopefully can figure out how to get them on here.

The chiller does a great job. The temp in the res is 60 to 61F. From what I can tell the temp in the pots is 63 to 64F. I should mention the pots are 48L coolers so the temps in them don't change very fast. Also, each pot has an air pump with a 6" round air stone. These are great air stones. This is the first grow using the coolers. Thinking back; I think the problem probably started in my veg room. They are in buckets in there and the temps do getup to 70 to 72 F. I don't have a chiller for that room. When the flower room is empty they get moved over.

Hi there Herb & Suds. I'm not sure about the test strips. It only says for testing free chlorine and will test from 0 to 10 ppm. The area on the color scale I was interested in is 3ppm and 5ppm. There's nothing between 3 and 5ppm, but for what I was using them for that's ok. When I added the chlorine to the RO water the color was over 3, but under 5ppm.

I'll check real close concerning the possibility of light. I don't think that's a problem because I have never had anything growing in the res. Res is always very clean and it's not possible for light to get into the pots. Never anything growing in the pots... at least nothing visible.

The Older Guy said:

The temp in the res is 60 to 61F

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that's a bit cold IMO. 65 to 68F would be better

I’m using about the same water as you. I run 600ppm well water through an ro then uv to a stainless storage tank. Have always had root issues. I don’t think there are any ferts that don’t react with chlorine. I am using pool shock atm. It does seem to work. Even though it shows 0ppm after mixing. I dilute 1.4g 65% shock to 1 L then 1ml/L to treat. I’m also using silica and it does seem to toughen the roots up making them less prone to attack. You may want to give that a try.

Yes, rkymtnman, I agree, but I'm keeping the temp down out of desperation because of the root rot. The temp at the roots is generally 62 to 64. A little better, but still on the cold side. I read someone on here keep the root rot away by keeping the water around the roots at 62. I believe I remember reading that when the temps are low like that that growth slows... not sure.

Hey Turpman. Thanks for sharing that. I even used a stronger solution and it still came out to 0 ppm of free chlorine(started with between 3 and 5 ppm) so I didn't dare leave it that way so I also added the amount of H2O2 I normally would have(8ml of 3% per L). I also use silica... Power SI. I was hoping someone on here was using nutes that had no affect on chlorine, but from what you just said its not likely.

The Older Guy said:

I believe I remember reading that when the temps are low like that that growth slows... not sure.

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you are correct. 65F is usually the lowest you want to go for that reason

do you have access to nutes other than Remo? it would be interesting to see if another brand would react differently. i know for sure that GH maxibloom works well with HTH. and it's probably helluva lot cheaper than remo too.

@The Older Guy
just read something interesting on the remo faq page
is remo organic?
we are a organic-synthetic hybrid line

Hi rkymtnman. I can get pretty much any kind of nutes sold in Canada. I buy local and also over the internet. A lot of time It's priced lower on the net and as long as you spend a $100.00 or so there's no freight. Actually; I was hoping someone on here was using nutes that didn't affect the chlorine. I wouldn't mind changing, but I hesitate to switch to another brand and find the same problem. I don't think Remo is organic, except for the Velokelp and I don't use that. I'm not sure what they mean by organic-synthetic hybrid line. I'll try and find out.