(DWC) Slightly smelly rez & salt buildup?

Hi guys&girls,

My first dwc run after lots of soil & coco runs is into its 3rd week now with 2x blueberry-OG seedlings from barneys that I germinated in root riot starter cubes.

Transplanted into a 2planter system 70L max 10 days after sprout.

Plants gave been in the system now for 10days making them 20 days from sprout.

I filled the rez with RO water to the bottom of the net pots the gave a mild CANNA START solution
PH 5.6
PPM [email protected]

I'm veging using 2x marshydro300 total watts from the wall 280 ' hanging them 24" from the plants
Water temp set to 18c with a 3c drift
Room temp 24c/27c night 18c/22c
Humidity 30%/50%

Topping of with 50/50 tap/RO

I've done 1 rez change so far ' cleaning with h202 then filling with RO water ph 5.6 ppm [email protected]

Since I done a rez change I've noticed white salt build up all over the bottom of the top tray what holds the plants? Also on the airlines too?

There is a slightly fish tank kind of smell that doesn't smell bad but doesn't smell good lol

I've been using a product called SILVER BULLET ROOTS and it said it should be good in your rez for up to 5wks as a h202 replacement?

Here is some picks...View attachment 4107175 View attachment 4107177 View attachment 4107178 View attachment 4107179 View attachment 4107180 View attachment 4107184

The plant haven't reacted bad to the hike in ppm from 300 to 600 but maybe it's too much nutrients in the rez causing all that salt build up?

I'm doing a full rez change and cleaning the rez and stones/airline's with some h202 ' rinsing with walm water then refill with 50/50 tap/RO with a EC of 0.1 then add 400ppm of DUTCH MASTERS GOLD RANGE ONE GROW 1-0.7-3
PH set to 5.6
Let it drift to 6.3 over the next day or too then top off and adjust ppm to 500?

Sound OK guys or am I missing something?

They look okay to me. I think it's just nutrient salt build up.

If you are using H202, I would not be afraid to clean the res. in between changes if you can be bothered.

I think the PPM part is subjective.. I was feeding seedlings 600-900PPM (ECx700) and they were still hungry after a few days. If you are feeding your girls 600PPM in the pics, they seem to be okay with it.

Your PH goes up by 0.6-0.7 in a day or two? (Maybe someone can chime in on this as I would like to know to, is that too fast? And what would be responsible for that, they could use a slight bump in nutes?)

In Reference to the ph question, I've read a lot of dwc journals & descusions about ph rising/falling and from what I've gathered is '
a stable ph is a good thing, if you can keep it a's close to the desired level things should go OK?

A little drift up from your "SET point isn't a bad thing exp; set ph 5.6 Monday night , checked ph Tuesday night 5.8 so leave it, checked ph Wednesday night 5.9 leave it, checked ph Thursday night 6.1 leave it, checked ph Friday night 6.2 adjust back to set point 5.6 done?

I've also heard growers letting there ph drift all the way from 5.5 to 7.0 before adjusting ph?

I gave my plants a feeding of FORMULEX that recommended a feed dose of 10ml/L? In my 70 litre planter that's 700ML. I only had a 300ML bottle so I threw the lot in after adding my h202 product called (SILVER BULLET ROOTS) it's a product much like h202 but has some added things to prolong the life of the hydrogen peroxide in the water solution, can last in the system for upto 5wks before becoming non effective.

BACKGROUND EC/PPM

EC/PPM 0.4/180ppm tap water 50% RO =EC/PPM 0.1/90ppm

SILVER BULLET ROOTS 40ML recomended dose (PREVENTATIVE) measures for young plants

FORMULEX 300ML
1/2 recommended dose for young plants

TOTAL PH&EC/PPM
EC 1.2
PPM 620
PH SET 5.6

I don't know what the FISH TANK smell is all about though? Maybe I have a slight light leak in the net pots and that's causing some nasty stuff to start growing? I have noticed a little tiny bit of brown roots in a small area?

I don’t get salt buildup (which is exactly what you are describing) but it isn’t necessarily the cause of your root rot . If you go a long time between water changes (even with deep fryer like aeration) you could get that slight fish tank smell.
If your aeration is not thorough throughout the entire body of water there very well can be many anaerobic dead spots which give the bad bacteria the upper hand in a very short time. Even with incredibly saturated aeration you may still get the fish tank smell if water change frequency is for example once every two weeks. That’s because of slime (with or without the help of light leaking into the water) that isn’t diluted with water changes.
Me personally, I get the fish tank smell (I’ll smell it coming from my shop vac exhaust when doing water changes) when I go longer than 2 weeks between water changes. When I do water changes every 7 days, no fish tank smell.
I have 54 DWC containers (36-20 gallon Rubbermaid brute and 18-4 gallon square buckets) aerated ad ridiculum (totally not plumbed together each bin and bucket is isolated...root clogs/floods are impossible) and I get a little slime inside of half of my containers and I never once scrubbed the insides of the bins or buckets or the surfaces of the air stones (which also get slimy, much more so than the inner walls of the 54 reservoirs) and I my air stones never need cleaning either.
The air stones never fail .I’m talking 72-8” round blue ceramic and 36-4” round blue ceramic.
No problems whatsoever. This is the secret to problem free DWC. I tried everything and every combination and life didn’t get easy until I stuck to these following parameters. I would not steer you wrong. When you get a chance, try this:

TopOff- Only RO. No 1/2 tap
Nutes- Start making your own this way you have complete control. Fatmans formula will work for you.
pH Down?- No. If you need it you messed up.
pH Up?- Yes. 10% KOH
Hydrogen Peroxide?- No. If you do actually need it, it’s because your aeration isn’t as good as you think it is but it still won’t take the place of real aeration. Please look up the real industrial definition of aeration in Wikipedia. It doesn’t say anything about fluming water into water. So I hope you are using real big air stone aeration with a few inches of air gap between the high water line and the bottom of the net pot once it’s in flower or even more than a few inches of air gap for that matter. It’s OK to go a little closer in seedling/veg stage but I have done extensive side by side tests with DWC and flowering plants REALLY like as much air space as possible (just as long as the bursting bubbles moisten the roots enough) and this hybrid DWC/AERO method is the most surefire way to get huge monster buds, but not necessarily increased weight above a flowering plant with a waterline only 2 inches away from the bottom of the net pot as in a regular DWC.

I’m pretty certain you are getting the salt buildup from your 1/2 tap top-off. It should also be known that you cannot get the longest service interval for peak air stone performance if you use 1/2 tap top-off.
I go sometimes 2 weeks between water changes. I start the pH around 6.3 and it drifts down to around 5.4-5.5 in that time. I never check anything in between. I dont adjust pH.Set...forget...live your life.
PM me if you want to know my exact nutrient formula. I have 10 years of experience in DWC and I’m not a hobbyist. I’m a professional.

Just cleaned the res and filled with plain water 'added 40ml SBR and letting it run of 12h/24h? Not ph'd the water just let it sit at 6.6.

I can smell where that fish tank smell was coming from it's the net pot definitely ' I think the dripper system I build was maybe keeping the roots to wet and with the light leaks through the shit!! Net pots I think that what was causing the smell?

I unplugged the dripper and made some mylar covering for the system so not there is no light leaks and I also ran 2litres if RO water through the net pots to flush them out a little and now I will let the res of RO water and SBR clean up the rest?

Fingers crossed when u empty the res tomorrow and really fill with some grow nutrients ppm to 500 and ph to 5.7 everything will work out?

You've got a duplicate post in this forum. I replied on the other, but I'll copy it to this thread.

Your TDS might be too high for plants that young.

You'll end up with salt buildup on equipment during your grows. In between grows you'll clean all that up, and sterlize with bleach. During the grow you can just wipe it off with a wet rag if it bugs you.

Your water temps are pretty chilly. Try not to let it go too far below 18c/66f, and not much above 21c/72f

Bad smelling water is an indicator that something's going on, most likely from the roots. You should flush with tap. Try this:

1. Drain system
2. Fill to bottom of net pots with tap water and let run for around 30 minutes
3. Drain
4. Fill with plain RO and run for a few hours
5. Add 180ppm nutes, and then keep an eye on them. If signs of deficiency appear, raise TDS with nutes, 50ppm at a time.

Your plants looknice and healthy, so you probably just need to flush and bring your TDS down.

kaydeezee said:

Just cleaned the res and filled with plain water 'added 40ml SBR and letting it run of 12h/24h? Not ph'd the water just let it sit at 6.6.

I can smell where that fish tank smell was coming from it's the net pot definitely ' I think the dripper system I build was maybe keeping the roots to wet and with the light leaks through the shit!! Net pots I think that what was causing the smell?

I unplugged the dripper and made some mylar covering for the system so not there is no light leaks and I also ran 2litres if RO water through the net pots to flush them out a little and now I will let the res of RO water and SBR clean up the rest?

Fingers crossed when u empty the res tomorrow and really fill with some grow nutrients ppm to 500 and ph to 5.7 everything will work out?

Click to expand...

Once you get your aeration to the max , you no longer need a top drip. Not even for starting seedlings. With bubbles bursting everywhere in between the waterline and the top of the bin, you simply leave about half of an extra large jiffy pellet above the top of the bin with the rest of it getting wet with bubbles. The fan blowing on low will be drying out the jiffy pellet while the bursting bubbles are soaking the pellet. This makes the top half of the jiffy pellet not too moist. The tap root will pop out of the side of the jiffy pellet (but inside of the bin of course) and avoid staying in the super wet lower half of the pellet.
I just got 9 out of 10 to sprout this way. Top drip involves a method that can get clogged. My method cannot get clogged and when you run enough well maintained air pumps, this method becomes invincible. Just an aside, I know that doesn’t address your question.