How much water would you say you put through it before you had to replace it?
This would all depend on how dirty your water is to begin with. The filters are basically designed or capable of filtering a certain total weight of the dissolved solids. If I remember correctly, this is something like 5,000 mg and it says either on the box or the documentation that comes with it.
hes right though. you will eventually have problems with your plants if you dont monitor the ph. If you need to add a nutrient your ph will drop in the water and you will be feeding them acidic water and nutes the plants will still look great until the 1st sighn of def then you have to flush because in soil it takes a while to go bad but when it finally decides to show you its going bad it goes bad fast
This is really a misconception, for reasons I mentioned in my first post and I can elaborate a bit. For one thing, some growers barely add anything to their irrigation solutions. Even in cases when you do, different nutrients will influence the soil solution pH differently. Ammonium-nitrogen (present in high amounts in many synthetic fertilizers, also may be present in manures in natural form) has been shown that applications can be followed by a sharp drop in pH, followed by a slow rebound.
A healthy soil/living soilless mix will typically rebound. Soil itself is basically designed to resist sudden changes in pH. It has cation exchange and buffering capacity. Cations are positively charged particles (ions), including H+ (hydrogen) and many that are required for plants (NH4+, K+, Na+, Ca++, Mg++, Zn++). Humus and clay particles are minute, and feature these [predominately] negatively charged 'sites'. They attract cations; the greater the CEC of a soil or material, the more nutrients it is able to hold.
As well the higher the cation exchange capacity a soil has, the greater the buffering capacity (ability to reduce pH change) under the right conditions. CEC comes overwhelmingly from the humus and clay content of a soil. Other materials like sphagnum peat, coco coir, vermiculite also have a measurable CEC. Perlite and rockwool have virtually no CEC. Clay and humus (which comes from decayed organic matter) have excellent CEC as well as humic substance content. Both are denser materials, but humus is spongy and holds moisture well. Examples of humus-rich materials are compost, earthworm castings, and forest humus. Microbes themselves are small enough to be involved in cation exchange (i.e. they have 'exchange sites', places where ions bind), as are roots (the fine root hairs).
The thing is that most potting mixes, while deigned to mimic soil, do not typically contain any soil (loam). They may contain composted materials or earthworm castings, but are mainly sphagnum peat based. Again, sphagnum peat is quite acidic. Although it has a cation exchange capacity, it also has/can have a great deal of reserve acidity (a tendency to hold on H+ cations). Very simply put, the more H+, the lower the pH. Coir is a better material to start with, as it may have a pH closer to 5 or 6.
This is where base cations come into play. Base cations are the following: Na+, Ca++, Mg++, K+. The later are the more important ones as these are primary\secondary plant nutrients. Simply put, base cations counteract acidity by reducing the over-all ratio of H+ cations and forming alkaline compounds- like carbonates.
Remember those carbonate compounds I was talking about in my last post? Lime/oyster/egg shell flour is calcium carbonate. Dolomitic limestone contains magnesium carbonates (more or less dep. on source but over a certain %).
When you apply lime to soil or potting mix, much of it exists as the precipitate. Solubility in water is pH dependent. A bit of the lime is immediately going to ionize or dissociate into the soil solution. Another portion of the applied lime will also react with the acidity to form carbon dioxide and water. Some of this is going to dissolve in the soil solution, forming carbonic acid, which dissociates to bicarbonate. Bicarbonate salts as a rule only exists in water and being salts they are electrically neutral.
All of this, forgetting about equilibriums and ionization constants (because fuck em right?) releases those Ca++ and Mg++ cations, which are plant available... Being
divalent cations (having more electrons than monovalent H+) they have a greater potential to displace the reserve H+ (acidity) and occupy more of those exchange sites. When that acidity goes into the soil solution, it may go on to form insoluble or electrically neutral compounds, or go on to react with more of the lime precipitate, and on and on it goes.
That's just from a strictly 'chemical' soil sciences perspective... I don't have the time to get into the biology right now and you'd be reading ten more paragraphs if I did.
I can also tell you that I never ever do anything to adjust the pH of any solution I add to the soil. I do not use liquid pH Up or Down whatsoever. I do not pH test my soil as a rule. That is something I rarely do and whenever I do I get something acceptable. Again, pH isn't supposed to be constant or homogenous throughout (it's not in nature). Some fluctuation is acceptable, and anything between or around 6-7 is acceptable. Don't put a lot of faith in what your pH pen or whatever is telling you if you're a soil grower.5.9 is probably okay, 7.2 could be just fine. You're not going to know what the exact pH is between the root-soil interface (rhizosphere) and it would vary at different times and places through out it and the rest of the soil.
Whether I sound like someone who doesn't know what they are talking about is for you to determine.
Ive been using Zerowater regularly. If I wanted to give her a supplement what would you recommend that's fairly cheap and effective? I went to the local greenhouse supply yesterday and the nutes they were selling were 300 bucks and I really don't want to cough out that much $
I only use General Organics CaMg+ for the purpose, since I use rain water that is typically under 10 ppm. I use the lowest amount unless I see an indication the plants need more (available) calcium. It is made from dolomitic lime and plant extracts and notably contains no calcium nitrate.
I still add more dolomite lime before planting (I recycle/mix a lot of my soil as well), and I also add Azomite. This is a remineralizer, and there are similar (enough) products from other sources: e.g. Excelerite, Rare Earth sold for the same purpose. These are ancient seabed and\or volcanic deposits that contain a wide spectrum of minerals, and may also contain humic/fulvic substaces.
