Pale Yellow Substance in DWC res

[AspenCultivator]

Day 7 from seed
2x2x5 tent
Feminized HSO Blue Dream
Res temps: around 73*F
Air temps: 78*F day 71*F night
18/6 schedule under HLG-135 QB
RH: 38-43%

Fresh res water yesterday, 3.5 gallons tap water that sat for 8 hours. PH 7.5, PPM 275
Added 3/4 tsp Gen Hydro Defguard (label says 1 tsp / gallon, so I quartered it and added 3/4 tsp total.)
Added PH down to 5.7
Res is at 330 PPM

Today after 24 hours, the PH was up at 6.34 and the PPM 330. I added PH Down to 5.7. PPMs now around 360.



A picture speaks 1,000 words, so here's two of them.

The first thing I noticed are the bubbles. Just a single layer of bubbles across the entire surface.

And here you can see a close-up of the pale-yellow substance that's building up. It's also on the surface of the bubbles towards the top of the image. I appreciate any help!

 

[TorturedSoul]

Well, since that particular fungacidal / bactericidal product is almost pure (98.85%) Bacillus amyloliquefaciens strain D747, my guess is that what you are seeing is a bacterial colony. Or the dead remains of same, I suppose, if there's nothing in there for it to eat.

 

[AspenCultivator]

Thanks for the reply. Can you point me in the right direction on how to use this product? I know I'm aiming for a live res (as opposed to sterile) which was why I was going for the Hydroguard in the first place.

Is it too early for Defguard? Am I using too little/too much of it? Do I need to wait until I add in nutrients? I appreciate the help.

 

[TorturedSoul]

I can't, no. In regards to hydroponics, I have always personally favored the synthetic (which is not to say inorganic, because synthetics also contain carbon/etc. ) nutrient world, in which I could aerate my solution "in an extreme way" if I wanted without worry of runaway microbial growth, and dump in H₂O₂ when needed (or just "when wanted," for a nice O₂ boost when it quickly decomposed) without fear of killing same. In other words, all the "OMRI" type discussions are mostly just opportunities for me to learn, not teach.

But we have plenty of the "other" crowd here, and it's my hope and expectation that one or more of them will be along shortly to enlighten the both of us.

EDIT:

I did find this at Planet Natural's website, via a quick web search for information about Defguard:

DIRECTIONS FOR USE:

Foliar: Mix in water and apply at a rate of 1- to 12-oz per 3,000 square feet (0.5 to 6 quarts per acre) in sufficient water to achieve thorough coverage of the crop canopy. Begin applications at crop emergence, transplanting or when conditions are conducive to disease. Repeat every 3 to 10 days, as needed.

Soil: Apply at a rate of 1- to 9-oz per 5,500 square feet (0.5 to 4.5 pints per acre) to control soilborne diseases infecting seeds, seedlings, roots, crown, stems or other plant parts in contact with soil. Follow-up (post-planting) applications can be made every 2-4 weeks.

Cutting or Root Dip: Place basal end of cuttings or bare roots (individually or in bunches) in a suspension of 1 to 2 pints per gallon of water. Immerse for 5-10 seconds immediately before planting.

Those application rates lead me to believe that this is a rather "potent" product, and that a little dab will do you (as they say). Half a pint per acre. . . .

 

[AspenCultivator]

That's pretty much what I've found as well. Thanks for doing some digging though! I took a look at Hydroguard, and that product has a concentration of bacillus amyloliquefaciens at 0.038%. That is freaking significant compared to Defguard. Hydroguard also advertises 5ml / gallon, which works out to 1.01 tsp / gallon of water. Defguard recommends 1 tsp / gallon as well, but the concentration is at 98.85%!

Needless to say, I'm thinking I'm going to ditch the Defguard. It seems like it's way too hot for this application, and I don't understand why my hydro store guy would even say it's something I should consider.