EI DOSING USING DRY SALTS

[dw1305]

Hi all,

Reducing the KH to half should in theory reduce the pH by ~0.2 if you have the same CO2 levels, so a smaller pH reduction relative to KH is normal. The connection between the KH and pH is on a logarithmic scale.

What @hax47 & @Andy Pierce say you need to reduce the alkalinity (dKH) to below about 4dKH before pH will drop much below pH8. That is why @_Maq_ has used acid neutralising capacity (ANC) as a measure of carbonate buffering in <"Some handy facts about water">.

That is partially why I don't like a pH value without an indication of carbonate buffering (alkalinity (ANC)), it doesn't really tell you very much. Conductivity is, in some ways, <"a less useful measure">, but it is much easier to measure and a linear scale.

If you don't have many ions of any description, you don't have much carbonate buffering, it is just nice and straightforward.

cheers Darrel

 

[keef321]

Conductivity is, in some ways, a less useful measure, but it is much easier to measure and a linear scale.

From reading your advice on this, in other threads, is why I bought a EC / TDS / Temp meter. I can do my 50% water change (with 50% RO) and aim for a simple 50% reduction in reading compared to tap water 😀, simples.

Funny enough, when I changed over to 50% RO, I noticed my GH reading did not seem low enough, I expected it to be GH 6 ish, but it was a 10-11. My EC / TDS meter reading showed the mix was correct. Eventually I checked the GH of my tap water, it has increased over the months from 13 to 20. I don’t particularly check the GH, so I don’t know when it changed, but it certainly has risen. I was hoping with the RO mix my GH would have dropped to 6, so I could potentially try some green neon tetras in the future 🙄, but instead im just going to be happy with the lower KH 😂😁 for the plants

 

[_Maq_]

Have you done the experiment of FeCl3 vs Fe-EDTA in your system?

Only marginally. While performing some of the tests of mine, some plants suffered from iron deficiency upon given circumstances (high pH). I've compared the effects of ferric chloride, iron citrate, and Fe-EDTA. The results were identical - some species prospered, others can't utilize neither of the three.

water report claims pH of 7.4 which isn't possible for atmospheric gas and pressure

I wonder what are the regulations for these measurement. It is obvious that tap water is cold & under pressure, so it contains more gasses than normal equilibrium. How do they handle this? I don't know.

they think iron deficiency simply arises from EI dosing (EI dosing causing high levels of nutrients blocking iron).

There's a great deal of truth in that. Phosphates.

Only when I dose iron chelates on a separate day, can I stop iron deficiency.

But this is mandatory! You can never dose micros (esp. iron) with phosphates. I always separate them by several days to restrict their interactions to minimum.

I can do my 50% water change (with 50% RO) and aim for a simple 50% reduction

I'm of the opinion that once you have RO(+DI) system working, it's a pity to blend it with tap water. Yes, full mineralization requires some investment in proper chemicals and dosing stuff. But then, then you enter the field of unlimited possibilities - you have full control of the water in your tanks. For me, it's a bliss. And the foundation of any success.
And, of course, it's the essential condition for performing all my experiments.

 

[keef321]

I'm of the opinion that once you have RO(+DI) system working, it's a pity to blend it with tap water. Yes, full mineralization requires some investment in proper chemicals and dosing stuff. But then, then you enter the field of unlimited possibilities - you have full control of the water in your tanks

I agree, but for me the problem is storing the required amount of RODI water within the house (outside it may freeze). I want to eventually upgrade from my 60P to 90P and that would be a lot of RODI to make and store. just now mixing with tap is a happy medium……we will see if this changes in the future 😂

 

[ian_m]

but for me the problem is storing the required amount of RODI water within the house (outside it may freeze).

When my mate kept marine fish (in the early 1990's) , he stored the generated RODI water in an outside water tub, with a 50W aquarium heater in it (set to lowest thermostat setting) and never had issues with the water freezing.