Ph Dropping

I've just come off fixing my ph from swinging WAY too high in a short time (it was not normal ph drift). I replaced the water and flushed, things seemed good until a few days later. Now my ph is slowly drifting down from 6 to 5.5 in the course of half a day. The plants are getting worse.

It started out as ph spotting, but grew into mg, cal, or phosphorus deficiency (I strongly believe it is the mg that is locked out and they are also a little K deficient in parts, yellowing has occured as well but that came with the spotting).

The scary thing is that the runnoff from my buckets when the water is running (the whole light cycle for hydro) is coming out a full (.1) lower than what is in the rez? What is causing this to happen?

I have six 5 gallons buckets with hydroton in a recirculating drip system with a 15 gallon reservoir. I use ice to keep the rezzy around 70. Two 400 Watts

I use RO water with 1 tsp per gallon of calmag, some potassium silicate, advanced nutrients micro, grow, bloom, a little supervit, and some compost tea/sweet. Would someone give me reccomended amounts for say 10 gallons of these ingredients?

I have changed the water, twice, and done a MASSIVE FLUSH with RO water and clearex. However, the ph is still coming down.

I WANT TO FIND OUT WHAT IS CAUSING THIS:

MY THOUGHTS:

1. I read somewhere that there is an excessive amount of K uptake in the transition week. Could this be causing my ph to drop?

2. Root rot? I dig down enough to see the roots and they look totally healthy. Still I added some DM ZONE (same purpose as H2O2) to kill all the bacteria, rot, etc. but I am still having the problem.

3. Too low ppm? I used to do dwc. Then each plant got 3 gallons and roughly six tsp's total of the Advanced 3 part formula, but now that they are all on the same reservoir I am worried that I am not adding enough. My ppm's are anywhere from 600-700ppm.

I am pretty sure these don't have anything to do with it: incompatibility of nutes and additives, evaporation (I lose some water, but I don't think that could cause as much flux as I am seeing), or my reservoir being too small.

Any help is appreciated as I have called the tech support at advanced and local hydro stores and even they have no idea what is going on. Ph should be rising!!!

When pH begins dropping like that, it usually indicates the presence of bad bacteria. Why do you have to add ice to your reservoir? How hot is this grow area? I think you need to find a way to improve your ventilation, and get temps reasonable, and see what happens. I'd lay off the organics for a while as they increase microbial activity in the root zone (not good if any disease is present). Also, your ppms sound kinda low (especially since you use additives), for a hydroton drip system.

Yeah, I figured it was bacteria, so gave the res a GOOD cleaning and a MAJOR flush. I have also added the zone a few days ago and I thought that was supposed to kill stuff pretty quickly? I pray this reverse swing just STOPS tomorrow. Maybe I should add some H2O2? I only have the 3%

Should I add some hygrozyme?

Temps run from 75-83 or so in there, saw the res get up to 78-80 degrees at one point, so the point of the ice is to cool it down. It holds more oxygen and prevents bacteria that way. The ice keeps the res to roughly to 68-70 degrees

Is the ice pulling something out of the solution?

I agree that the ppm's are low, could this be contributing to the problem? Of the ingredients I listed can you reccomend amounts for a 10 gallon res and desired ppm's?

Oh, I am in the first week of flower, fyi (see "my thoughts" #1)

I'd try the h2o2, you should try the 35% available at hydro shops (if possible, don't get it on your fingers! ouch!). I don't believe ice is hurting anything, as far as the nutes, I'd seriously toss the compost tea, use 1/2 tsp. each of the k-silicate and cal mag, and just use the recommended amount (or a little less) of the advanced nutes (not personally familiar with those). Desired ppms for regular hydro, for me, would be between 1300 and 1500 (about 150 will come from the additives). I know there are lots of people here claiming to use extremely low ppms, but maybe they do dwc or aero. Unfortunately, with your room consistently above 70%, I forsee problems - if your buckets get up to 80 degrees for a significant period of time, the roots can turn to mush and rot away. I bet it is very hard to add the right amount of ice to regulate the res temps. Unfortunately, res chillers are expensive, and generate a lot of heat. So you need to figure a way to either ventilate the whole area, or use a/c. Others will tell you to move the res to another room, but that is WAY easier said than done. Good luck.

How much H202 should I use per gallon: of the 3%?
Of the 35% (Is it 3ml per L?)?
And is it just for a flush or do you recirculate for a bit?

Do you think the low ppm's could contribute to the lowering ph?
You use 1300-1500 ppm's in what? recirculating? how many?

Quick question, you say": Unfortunately, with your room consistently above 70%, I forsee problems" Are you referring to humidity? Because my humidity is around 40%. I have a humidifier to keep it up actually.

Sorry I meant 70 degrees (where is that freaking symbol?!). The 35% h2o2 has directions on the bottle, it's like 2 or 3 ml/gal, I think. Theoretically, then, you should use 10 times the amount of the 3.5%, but this would be a real shitload...and you'd be using lots and lots of it...I say get the good stuff, it'll probably be cheaper in the long run.
What I was trying to say, basically, is that hydro does not work very well in a hot room. Adding ice to the res is a good idea, but unless someone is constantly in the room, on "ice patrol," it will be next to impossible to keep res temps in the proper range. I notice you have not responded to my inquiry about ventilation (or lack thereof!). At some point, to do hydro properly, you will need ventilation. There is a big ventilation section at most home depots.
FWIW, if your only issue was the lowering pH, you should be aware that there are some plants that, in hydro, will cause the pH to drop consistently, while being completely healthy. So pH dropping, on its own, is not necessarily an indication of a problem. But, in your case, I think its a bacterial/heat issue. Good luck.

Dude you can assume that I have ventilation as it is a requirement in any setup. Just because I don't mention it doesn't mean it isn't there. I have ventilation, plenty of it, lights are cooled by a blower. And the acceptable range for plants goes up to 85 (do u think plants don't grow in areas over 70 degrees)? Also, you can say that I can't keep my res cool with ice, but it is an acceptable and fully working method. The ice does a great job (I checked the temp every 30 min) of keeping the res temp in the acceptable range.

It may be bacteria, but I am 100% it's not from the heat. My air and temps are great.
Can I get some input on "my thoughts: #3?

Acceptable temp for plants is NOT the same as acceptable temp for roots. Never in nature will roots remain above 70 degrees. Hydro is much different than nature. As to your ppms question: 1300-1500 is about right for a drip system, at 700 ppms you will probably have a mg. deficiency, if not a full-blown deficiency of everything. So, maybe, instead of mg. being "locked out," it is just deficient. I can't see how people use very low nutes and succeed, unless their meter is out of whack.

I am doing a full cleaning, replacing the piping, etc., in case of bacteria. If that does not fix the problem I will do another flush, followed by a higher dosage solution.

As for the root zone, I really think my temps are fine. I have used this setup successfully in the past. The only change has been my nutrient regimine.