pH Changes - Hard to Control

[OU812]

Started germinating seed 7/22. Set up seedling in Hydrofarm DWC Bubbler. Using Viparspectra 450 in a 32"x32" tent with good ventilation/air circulation. My tap water comes out at > 9 pH. Using Fox Farm nutes for hydro, full strength at this point. Replacement water w nutes always adjusted to between 5.5 and 6.2. Within a day, pH goes to > 7. I'm changing the water every other day to bring the pH down but, doesn't stay there. Using Hydroguard, too.

I tried 1/2 strength nutes, RO water w cal mag. Nothing helps to maintain pH within range. I've read and re-read everything I can find on here about hydro and bubblers and can't figure out what I'm doing wrong. Any help anyone can provide will be much appreciated!

[Qwertywill]

Are you using ph down as well? Perhaps have a second pump go until your ph stablises in a bucket, add ph adjustment as needed prior to feeding.

[OU812]

Yes, using pH Down. I'm not sure I understand your recommendation to use a 2nd pump, etc. Would you mind elaborating a bit? How does this work? Thank you for your help!

[Qwertywill]

Second air pump to circulate the nutes and balance everything out prior to giving the new mixed nutes to your plants. You can adjust the ph that way.

[OU812]

Okay, Qwertywill - I totally get that. Thanks for your help!

[RosettaStoned]

Assuming you are using pH down, what happens after few days if you adjust pH instead of change? What is water temp? Does EC go up or down? Are you using silica?

I have to mix my calmag and silica, with a pH adjustment, the day before. It stays more stable that way. I do believe pumping a lot of air through the water raises pH, although I doubt you are.

is that the current plant you are growing? Full strength nutes is a lot for a plant that size. Have you looked at the roots, if it has any to see? Campesino let me know that a bacterial infection can raise the ph but the EC needs to drop I think. He would have a lot more insight to your problem.

[OU812]

Yes, I am using pH Down to bring the pH down to where I want it (at this point, 5.5). After a day, sitting in the container before adding to the plant setup, the pH creeps up to about 5.8. There are no roots to see yet however, I've been adding Hydroguard with all the water I've used.

Today, temp is 82, rH is 41, pH is 7.4 and, ppm is 634. I added pH Down to reduce pH to 6.5, ppm unchanged. RosettaStoned and Campesino - any thoughts? Thanks for your help!

[9fingerleafs]

it sounds rather simple to me, your very alkaline tap water must have high concentrations of something the plant does not use (like sodium) so when it uses the nutrients all thats left in the reservoir is what ever your tap water contains. try using only RO water and nutes,

[9fingerleafs]

Geez then I got no idea what it could be. Like the others said. Without EC readings it’s very hard to know if it’s a small phenomenon when nutes are used and a very little concentration of something else remains or if it’s a big problem impeding nutrients from being absorbed. The plant is still rather small. You will have to keep an eye out for deficiencies caused by too high ph in order to react. The whole issue could go away as the plant gets bigger and drinks more

[OU812]

I am tracking ppm. Today, it measured 634. My (limited) understanding is this represents about 1/2 the full-strength nutes - about what this 2 week old plant needs? It's growing nicely and doesn't appear to be pH stressed so, perhaps I'm over-thinking it. Thank you for your help 9fingerleafs - much appreciated!

[9fingerleafs]

No worries in that case consider your ph pen may need calibration? If the plant is healthy and happy don’t hange a thing. Btw I feed the same dose all cycle around 2 EC or 1000 Ppms.

[OU812]

Changed over to RO water last weekend. pH is still hard to control. Measured this morning and pH was 7.1 545ppm. Used GH nutes this time and the water needed no pH down - got to 6.0 on it's own with the GH nutes. Left it sit for a couple of hours and still 6.0 657ppm. And, here's latest pic. Seems the brown spotting isn't as widespread as it was a week ago. Pruning the f'd up leaves (once more than 50% spots). Tent temp is 79 degrees, rH @ 51%. I added an airstone to the reservoir, checked light placement and fans and all is set up well. I wonder if it was the Fox Farm nutes f'ing up my water?!?! The GH nutes feel better (to me and, hopefully this little bitch). I've calibrated both my meters. I want to thank everyone for your wonderful suggestions! Gave me a lot to consider and research. This is only my 3rd recent grow. Hopefully, I can fine-tune my setup and get a decent yield. I tried coco, super soil and, now, DWC. Couldn't get pic to upload. I'll try again later today.

[NAKEDGARDENER]

My set up for future is gonna be dwc along with top feed rings for drip feed, looking forward to setting up a hydro system, RO water well I also considered this, however, now I use it for drinking, and not feeding my plants, since I use soil right now and don’t want to add too much nutrient. RO for me will be for flushing I guess

[DankwingDuck]

Top feed rings only benifit the dwc when it is a seedling . Once your roots hit the water they are useless . Just something to think about before to spend money . You can eliminate the top feed all together and just water by hand twice a day from the res with a cup . For the limited time the top feed will be used I don’t think it’s worth the money imho

[NAKEDGARDENER]

Yes I know top fed is only good when they are small, so do continue to use em late into their grows I see, but I would use it just at the beginning before root zone is in the res. Thanks dank, good advice

[DankwingDuck]

Can I see a photo of the roots please ? And a photo of the water in the res with the pumps on . Even if no roots showing please still give pics of net pot and res water .

[DankwingDuck]

Btw your ppm is to high for a plant that small imho

[D.A.A.S.69]

It's almost impossible to know what the ph of RO, water is, it's supposed to be close to 7.0ph, but that ain't always the case.
RO, water is to expensive and a big waste of resources if you ask me.
But lots of people use it ,still.
Good Luck with your plants.

[NAKEDGARDENER]

I concur about R O, I only drink it now but it’s friggin expensive dead water at that

[D.A.A.S.69]

Amen NAKED, It's sure a big waste of our water supply.
Why not just get a big 55gallon drum, and catch rain water ,an save your money.

[DankwingDuck]

My RO water comes in at 7.0 always but I buy it by the gallon it I could see how an in home system might fluctuate . I have stopped using RO water on my bigger plants and only use it now for my seedlings . My tap water comes in at 110ppm after sitting over now night so I only use RO water for seedling to keep the Ppm low at the start . After the first few weeks the minor Ppms in the tap water don’t really effect anything . IMHO

[OU812]

I think I solved for my inability to control the pH. I've done 2 other grows (one coco; the other supersoil) and, now DWC. I tried tap water, then RO. Only when I switched nutes from Fox Farm (hydro) to GH am I able to control the pH.

Now: using tap water, GH nutes (according to Nebula's feeding schedule), checking water 2x daily (no adjustments needed last couple of days) for pH and ppm.

Moments ago, I topped-off the reservoir with the same. pH 6.3, ppm 534. Most importantly, pH is STABLE!!! Finally! F*CK!

DankwingDuck what should my ppm be at 3-4 weeks? I've read countless versions. What do you add to RO at the seedling stage? My RO water is bottled, from WallyWorld @ 89 cents/gal. Always 7.0. The roots are nice and white - not able to upload photos now, not sure why (not this site). There isn't much in the reservoir - very clean but, a bit cloudy. No sediment on the bottom. The roots look really good.

D.A.A.S.69 Ain't no rain in this part of the country for the time being. I'd love to use rainwater!

NAKEDGARDENER I love this GH waterfarm set-up with the drip ring. Works like a champ, despite not being terribly valuable well into the grow. There's no disadvantage, I can see, in using it throughout the grow - especially if you don't have much opportunity to water her throughout the day. I bought mine in a kit, from Amazon, for about $50 - all inclusive. I have zero motivation to build my own although do appreciate and respect that others do. It's a preference thing.

Thank you ALL so much for your encouraging words and helpful advice! I'm looking forward to a better grow and result with this grow. I get a lot out of the variety of advice I get through here and, whether I follow some, any or all of it, it's all valuable to me as it's helped me troubleshoot my problem. Thank you again!

[DankwingDuck]

I stopped basing ppm on week and I go by plant size. How big is she

[DankwingDuck]

As far as nutrients for the seedling stage I would use even parts of the base nutrient and then use everything else according to the bottle recommendation and then Use clean water to dilute the nutrient solution to the desired ppm when first planting the seedling into the DWC use clean water to dilute the nutrient solution to the desired ppm when first planting the seedling into the DWC Start your PPM’s at 50 and slowly work up to 200 when your plant grows to its first five finger node raisethe PPM‘s to 300 and slowly increasing the PPM‘s till 550 ,550 is going to be your max veg ppm’s

[OU812]

DankwingDuck she's about 15" now. Thanks for the ppm info, Brother! That's what I needed! Today, pH 6.5, 545ppm, temp 79, rH 61%. Still can't figure out why I can't post pics - it's not a GWE thang - more like my Google Pics not receiving what Ima sending to it. I'll get that fixed this weekend sometime and post up some pics. Thanks, again, for all your help! I really appreciate it!

[NAKEDGARDENER]

OU812 thats awesome my friend well done... yes I am glad you are using the top feed system, it’s something many have recommended to me in the past and am going to use it for sure, please feel freel to let me know your results via a private message anytime. Good luck

[OU812]

NAKEDGARDENER I like the drip feed and maintain throughout the grow. It doesn't hurt anything. When I shopped around for a DWC kit, I chose GH Waterfarm because I've used it before (20 years ago). The drip feed didn't cost any more than any of the other set-ups I looked at. In fact, it was a few bucks less. I'm going to do a couple of grows with this set up and hopefully perfect my skills (or, get as close as I can). Maybe three grows. Then, I'm going to try coco for a couple, using the same pH control/nutes (for coco - not Fox Farm). Then I'll try a couple with super soil. Very interested to see, when the same "developed skills" are applied to each medium, what my results are and, specifically, what is the difference in the results. Tweaking as I go, to find the perfect set-up for me and my girls.

If you do go with GH's Waterfarm, I'd suggest buying an air pump with 2 outlets - one to the drip and the other to an airstone in the reservoir. The more air to the roots the better, from what I've read and am beginning to experience now. I found a cheapy double outlet air pump at Wallyworld for about $10. Works great and is very quiet.

Thanks for your help, Brother! BTW, I like your setup in the pic!

[NAKEDGARDENER]

Absolutely I intend to have at least two air stones per res, bro, only two 10 gallon reservoirs I think, was also thinking of mcgyvering some kind of res drainage system and refill via pumps and taps on the bottom of the reservoirs. I’m really glad things are working out for you brother and happy to be of some help, I hope to follow your continuing
progress.

[OU812]

Here's a pic from yesterday..

[NAKEDGARDENER]

Picking up nicely