Return to the Container Gardening Forum | Post a Follow-Up

 o
5-1-1 and ph

Posted by woohooman San Diego CA 10a (My Page) on
Mon, May 27, 13 at 21:59

Here's my quandary and question.

I made 50-60 gallons of a modified 5-1-1 this year. The modification was 1 and 1/2 parts turface and 1/2 part potting mix replaced the peat component. Everything else remained the same.

Here's the issue. The lime is supposed to balance out ph and supply Ca and Mg, right? Well, my municipal water is basic. So, what may be a balanced ph at the beginning would probably be more and more basic as the season progresses, no?

Should I be adding a quick acting gypsum if I'm shooting for a ph slightly on the ACIDIC side. I have some of this stuff for my "dirt" garden. Should I add a tad to my containers also?

Thanks

Kevin

Here is a link that might be useful: fast acting gypsum

This post was edited by woohooman on Mon, May 27, 13 at 22:12


Follow-Up Postings:

 o
RE: 5-1-1 and ph

Most people's tap water is toward the basic. Mine for instance is 7.8. The mix doesn't trend toward the basic very much over time. Gypsum doesn't lower the pH at all, it just supplies calcium. The sulfur that's included with the gypsum would lower the pH but it would take a long time. I recycle some of my mix every year and the pH of the mix is still plenty low enough. What I (and others) do to combat feeding plants 8 pH water, is to add a little vinegar to the water. If I add 1 tablespoon of white vinegar to 2 gallons of water, it lowers the pH to about 6.5 which is the approx pH of my rainwater. So IMO, don't add any gypsum or sulfer, and just add a little vinegar to your water.


 o
RE: 5-1-1 and ph

  • Posted by DWD2 10a, Sunset 17 (My Page) on
    Wed, May 29, 13 at 4:02

Kevin, pH management of container substrates is a big subject and there are a lot of great resources out there. Relative to your water supply, the alkalinity of your water is the bigger determinant of whether you need to adjust the pH than pH alone. If edweather can adjust the pH of his water from 7.8 to 6.5 with 1 tbls of vinegar (acetic acid, which is a fairly weak acid) in 2 gallons of water, then his water is not very alkaline. I would not bother with the vinegar with what he says he observes. Here is a link by the horticulture group at North Carolina State University that does a great job of explaining what you are asking about.
http://www.ces.ncsu.edu/depts/hort/floriculture/plugs/ph.pdf

Your water provider measures the alkalinity of your water & can tell you what it is. Whether they will is another matter entirely. They usually will.

Like all soilless media, 5-1-1 has its pluses & minuses. Your success is a function of how well you manage your media.

Good luck!


 o
RE: 5-1-1 and ph

Thanks ed and DWD -- I'll do a reading in a couple weeks and see what I come up with. Nice to know something like white vinegar might help.

Kevin


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Container Gardening Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here