Safe way to lower ph

[Leisurely]

Originally Posted by isurus79

There is absolutely no reason to lower the pH below 6.8 and there is no reason to increase your TDS (as stated previously). Be sure to add a Cal/Mag fertilizer with every watering and you should be doing well.

It may not be necessary to lower the Ph but it will certainly not do any harm, from my experience.

Without regard to Ph, I have used tap water to water my entire collection of about five hundred orchids for the past twenty years. All of the intermediate to warm growers did fairly well.

About two years ago I read something on Ph and decided to lower the Ph from 7.6 to about 6 and at the same time I switched to a Cal/Mag fertilizer that is, from memory, something close to 15-5-7. Everything has since flourished. I can't be sure if it were the lower Ph or the Cal/Mag fertilizer but I certainly don't intend to change at this point.

[cpeters5]

Jerry,
For about 3 weeks now, I started using fish/seaweed extract once a week in addition to the usual 20-20-20 fertilizer. It is interesting that just a dash of the seaweed extract will lower PH down by almost one point. (It does not affect the TDS value.) The baseline water has 6.9-7.0PH and about 35 for TDS. After adding the seaweed extract and fertilizer, PH 5.9-6.2 and TDS ~120.

Vandas, Cattleyas, Aerides, and hybrids responded very well to the new recipe. It is the first time ever in my 6 month of orchid growing that I can actually watch roots grow over night. It is a good feeling to finally see some healthy roots. Yay!
pax

[isurus79]

Originally Posted by cpeters5

Jerry,
For about 3 weeks now, I started using fish/seaweed extract once a week in addition to the usual 20-20-20 fertilizer. It is interesting that just a dash of the seaweed extract will lower PH down by almost one point. (It does not affect the TDS value.) The baseline water has 6.9-7.0PH and about 35 for TDS. After adding the seaweed extract and fertilizer, PH 5.9-6.2 and TDS ~120.

Vandas, Cattleyas, Aerides, and hybrids responded very well to the new recipe. It is the first time ever in my 6 month of orchid growing that I can actually watch roots grow over night. It is a good feeling to finally see some healthy roots. Yay!
pax

Pax,
You really don't want to use seaweed fertilizer more than once every 2 weeks. The fert contains auxins which stimulate root growth, however too much of it will cause the plant to build up a resistance to this hormone. This can cause your plants to stop growing roots at all.

[cpeters5]

Ahhh! Thank you isurus79. I am lucky that it was raining a few hours after I fertilized my orchids the last time. So at least the ones I kept outdoor should be OK.
Thanks for the tip.
pax,