r/Hydroponics • u/Original-Cloud2520 • 6h ago

Zero alkalinity

Is using RO water with zero alkalinity a good or a bad thing?

Or would it be better to mix it with tap water?

2 Upvotes

67% Upvoted

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1

u/DeepWaterCannabis 5h ago

Its just a thing, neither good nor bad - you just need to plan your nutrients around it. If you use RO, you typically need to supplement with a CalMag, depending on your plants needs

1

u/VillageHomeF 5h ago

you need to buffer it before adding other nutrients. very unstable yet easy to fix.

1

u/DeepWaterCannabis 5h ago

Huh? I just silica, then add my nutrients, then I add my CalMag. At that point it has buffers in it and is good to go.

1

u/VillageHomeF 5h ago

you should do the silica then the calmag and then the other nutrients. does the water get cloudy?

I've literally seen people get fired from commercial facilities for doing what you do. risky

1

u/DeepWaterCannabis 4h ago

Nope. I get zero precipitates. I let things mix well before each step, tho. Im also not mixing a concentrated solution, so mix order doesnt really matter to me. The water Im adding is the EC I intend my rDWC to be at, rather than an injection of food into the system

1

u/CostPlusSeeds 3h ago

It should be fine as long as you balance the pH and nutrients. I grow strawberries/lettuce, and I aim for a pH of 5.5 to 6.5 and around 600 ppm of MaxiGrow/MaxiBloom powder from General Hydroponics.

Starting with RO water is nice because it has nothing, while tap water has around 100-200 ppm of stuff that doesn't help you. Having too many dissolved solids (>800 ppm in my experience) can cause problems.

MaxiGrow has some calcium and magnesium, so even if I were using RO water I'd be fine. I'd be careful with CalMag; I've tried supplementing with CalMag in the past and it left lots of hard water deposits in my hydro system. If you're mixing your own nutrients rather than using a pre-made powder others here may have better advice

1

u/VillageHomeF 5h ago edited 5h ago

it isn't good to add other nutrients at zero alkalinity. usually you would add CalMag or another amendment depending on how you are growing. Normal tap water contains some calcium and magnesium.

Zero alkalinity is highly unstable and can account for wild swings in pH. it wants to pull minerals like copper, iron and lead from wherever it can get it. it will literally pull minerals right out of metal pipes