First time grower having Major ph issues - Please help!

[Jonas8952]

Here's the setup -

I built a flood and drain system with an 18 gallon res and a large rubbermaid bin for the flood tray. My medium is about 60% hydroton and 40% pea gravel. I washed the dust off the hydroton and soaked it for a couple of hours. I washed the gravel in bleach water and then rinsed it 9-10 times and soaked it for a couple of hours.

I filled my res with 8 gallons of distilled water and 4 gallons of tap water. When I was done, the pH was at 7.7 and the ppm was at 65. I started adding pH down and couldn't believe how much I had to add! I'm using a medicine dropper to add it, and every dropperful lowered it by only .1! Isn't it just supposed to be a few drops to lower the whole thing? I'm aiming for 5.8, and I can't believe how much it takes.

I finally got it down to where I wanted it by adding 10-12 droppers and I ran a cycle. Back up to 6.6. I'm going to let it sit overnight now. I've got an air pump with 4 stones attached running in it, but that shouldn't make a difference, right?

I don't know what's going on. I'm a brand new grower, so I'm sure I'm making some big rookie mistakes. I just want to be able to put my sprouts in the tray and feed and water them without killing them, but the system is so volatile, and I don't know what to do.

Help???

 

[MrBelvedere]

Re: First time grower having MAJOR ph issues. Please help!

Don't worry, you are doing it perfectly correct. 8 gallons is a lot of water to treat. So next time maybe just add a teaspoon of phDown at a time or something.

 

[paul keating]

Re: First time grower having MAJOR ph issues. Please help!

When you add your nutrients to the water, they should lower the PH as well.
So later on, when you have plants and start feeding them, you won't need to use as much PH down.

I tried a hydro setup once, and i just used some basic powdered nutrients.
If i used the full recommended dose, it automatically lowered my PH to the correct level (roughly).

At first, when you only use a weak dose of nutes for small plants, you might have to add a bit of PH Down.

 

[paul keating]

Re: First time grower having MAJOR ph issues. Please help!

And later on, when you start using nutes, make sure you put your nutes in the water first, check the PH level, then add PH down if required.
Not the other way.

 

[go4snypr]

Re: First time grower having MAJOR ph issues. Please help!

What are you using for ph down and how big is your dropper??

 

[paul keating]

Re: First time grower having MAJOR ph issues. Please help!

What are you using for ph down and how big is your dropper??

I was just using aquarium PH down, because i had a fish tank at the time.
It's powdered stuff, and i didn't really use a specific measurement. I just used a spoon, to put a little
bit in at a time, then checked it with my PH meter, and added more if it needed.

 

[Jonas8952]

Re: First time grower having MAJOR ph issues. Please help!

What are you using for ph down and how big is your dropper??

I'm using General Hydroponics' pH control kit. I'm just using a medicine dropper. It doesn't hold much.

I'm just scratching my head as to what could cause the problems. I drained the tap water/distilled water and filled it with 10 gallons of RO water. I added the General Hydroponics' Flora nutrients in 1/2 strength. The bottle calls for 1/4 teaspoon of each bottle per gallon of water, so for 10 gallons I added 1 1/4 teaspoons of each.

I'm still having the exact same problems, though. I'll adjust it to a perfect 5.8, then I'll run it through the clay/gravel mix and it comes out at 6.4. I'll adjust again (I find that three dropperfulls will take it to 5.8), let it sit a few hours, and run it again, only to find another rise to 6.4.

I'm still watering my babies by hand because I'm scared to put them in the tray and run them in a system that continually bumps up the pH every time they're fed. They're still young enough (sprouted 2 weeks ago) that I don't quite need to feed them yet, but I want this to be an automated system, and I'm really worried about doing more damage.

Any ideas? Is this normal? What could be causing my pH to rise? Should I be worried about putting so much acid into my solution?

 

[Jonas8952]

After a few days of monitoring and adjusting, I've planted my seedlings in their rock wool cubes in the flood tray. It's still going from 5.8 to around 6.3. pH after every cycle, though.

I'm only watering once per day, so I'm just going to balance the solution every morning before the cycle runs until it stops rising.

Am I doing the right thing? Am I putting my babies in danger?

 

[hydrodoc]

with all due respect, I was under the impression that you should use ph corrected water BEFORE you added nutrients. This allows you to run your nutrients longer before having to adjust. If you are changing your reservoir weekly it probably doesn't matter.

 

[Jonas8952]

I've read in several places, including posts in This thread, that you adjust ph after adding nutes.

So far, my plan seems to be working. The babies look great after their first couple of days. I'm just hoping that it will stabilize enough so that I don't have to fix ph every time I run the water.

I just have no idea what could be causing the problems. I haven't been able to find anyone else describing the same issue.

 

[go4snypr]

Yes, adjust ph after adding everything to your water that your going to add. then add the water to the res. I am not sure what to tell you about your ph rising. I know mine changes somewhat as well, but I am using rockwool. I used to watch it like a hawk, now I just monitor and make adjustments if I feel its getting way out. After I mix my nutes my ph is ususally 6.1 ish, I will add some ph down but not too much. this might put my water at 5.5, but over the next few days, the ph will (usually) rise, once it gets up to the 6.0 range I will do the same thing. You just have to watch that the ph doesn't start to drop. As long as the plant is using water and nutes at the same rate you should never get too far out, but if the plant starts using one more than the other your ph is going to change because the ppm has changed radically. But don't stress to much about the ph, just lower to under 5.8 it and let it climb over the next day or two. Once it is getting up over 6 then bring it back down.

 

[Jonas8952]

Awesome, that's exactly my plan. Thanks for confirming it!