JustSomeGuy

thanks for your help guys!

pearl

BaadPuTthyKat, thanks thats a lot of information to ponder.
I knew the answer wouldn't be a simple one.

I think I'll stay with 5 gal buckets and mix them complete each time.
So far thats worked for me.

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Pearl's Drip System ~ Fall Harvest 2006 ~ Live Predators

BaadPuTthyKat

EC or ppm readings are more important than ever on hard water areas, as this contains bicarbonates of magnesium and calcium, and often high borate content. These can cause potassium uptake problems.

The most common pH adjuster is phosphoric acid, which in hard water solutions will often cause crystals of calcium phosphate to form. These can quickly lead to deficiencies and hit the yield, as well as block drip emitters, etc.

In hard water areas is it often preferable to use nitric acid, and better still to use a blended buffered pH down solution. The exceptions to this are during the second half of flowering. If a large quantity of acid is needed to get your tap water to a useable range, it may be an idea to get a water analysis done. In any case, in HW areas, a weekly res change through flowering will save imbalances happening.

The plants will use more or less h2o dependant on size, ambient temps, RH, stage of development, intensity and duration of light, availability of co2, root temps and pH & EC, microbes, etc. These are all interdependant to some degree JSG. Thats why its hard to say something 'causes' more water uptake.

Some water companies over here add some pH adjustment, to save corrosion of copper pipes. The dissolved solids (ppm) and EC remain high, even though the pH reading is good. It's a good idea to know as much as you can about your water supply.

Freedom_Farmer

Hmmmm. My water comes out of our private well, and it is beyond hard! So, what I actually thought were sodium deposits are probably/maybe/could be calcium phosphate? Great Looks like I'm on the prowl for some nitric acid now.......

__________________
My first HYDRO grow.

"The prestige of government has undoubtedly been lowered considerably by the Prohibition law. For nothing is more destructive of respect for the government and the law of the land than passing laws which cannot be enforced. It is an open secret that the dangerous increase of crime in this country is closely connected with this."
~~ Albert Einstein, "My First Impression of the U.S.A.", 1921 ~~

BaadPuTthyKat

Ideally FF, I think a blended pH down, but it can be hard to track down. Higher nitrate levels are less critical than maintaining P-K balance, in the grow, until week 4 onwards of flowering. Then, I would use phosphoric acid again, just for the nute boost weeks 5-6. Anytime after that, and the pH will be dialled in.

I think you will be fine with 7-10 day res changes. Just remember that adding 'hard' tap water is actually adding up to 700ppm of undefined mineral content. Start and run with higher concentration, pmm, EC, whatever you want to use. This will maintain a good nute profile, over & above the background ppm/EC. I have used 1000ppm/ 1.4EC and rising for veg, and rising up to a max of 1950ppm/2.8EC at week 6 of flower, in NFT. pH 5.5 rising to 6.2, and kept inside these parameters. That EC is for really intense lighting, but you get the idea. Some strains hate high EC's though, best thing to do is....

Just a thought, is there any way of solar distilling your water? You would then have virtually 0ppm water. Try to remove the white crystals where ever you can, & scour it all off inbetween grows, IMO. Whatever it is, a crystal will tend to remove more minerals by growing in our mineral baths(nutes). Sorry, we kind of tracked off where JSG is at, but I think you get the idea.

Freedom_Farmer

Excellent idea. I'm sure I can rig up some type of distilling system. Thanks Kat, I'm going to have to hit the drawing board on this one!

__________________
My first HYDRO grow.

"The prestige of government has undoubtedly been lowered considerably by the Prohibition law. For nothing is more destructive of respect for the government and the law of the land than passing laws which cannot be enforced. It is an open secret that the dangerous increase of crime in this country is closely connected with this."
~~ Albert Einstein, "My First Impression of the U.S.A.", 1921 ~~