Adding Epson Salt. How Long Until?

ShowMeTheSmoke said:

I been following this thread along hoping to find a awnser to my question.

What is the best way to check soil ph that wont break the bank?

Should u add lime to a medium like promix hp to combat a mag def if the medium ph is off?

The only testing equipment I have on hand is ph pens and cal, mag, kh fish tank test kits.

Click to expand...

Best way to test pH is definatly a digital pH meter and a good one too. I have an all in one from essentials dose pH/ppm and temp of one probe. Cheapo kits just arent accurate, might look like pH 6.5 when it is really 5.5 or similar. Price wise a digital pH tester is better as it dose a lot more than just 3 tests and will last for years, a good investment.

I never used pro mix but most soils are the same and require lime, dolomite garden lime is 3 parts calcium to 1 part magnesium of the top of my head and the calcium is released a lot quicker than the lime so if your water dosent have adequate mag in to start with you will need to add a small amount, this would be a good reason to have a ppm meter as well.

A quick draining soil with perlite will produce less damp conditions and hence less acidity so another way to care for the soil pH. Wet conditions promote the bad bacteria and algae which make a lot of acidic waste compounds compared to the good guys!

Reading soil runff isn't accurate but will tell you some usefull things.

Firstoff the runoff will get lower and lower in pH or more acidic the more ferts are added, ferts are made from salts even organic ferts contain some salts, the more they build up the more they make the water (Runoff) that dissolves them acidic, this dose not mean your soil is acidic it just means you have a lot of ferts built up in the soil! A flush will lower these salts and take them away thus reducing the runoff ppm and increasing the Ph back up to normal levels. So a pH meter and ppm meter wont tell you if you have an acidic soil but will tell you when you have too much fertilizer salts built up and hence when you need to flush.

A way of identifying acidic soil is when the runoff next watering after a flush (when no or little ferts have had a chance to build up) is very acidic. To explain the difference ferts will lower the pH by adding salts to the soil, you know how much you have added and for how long so you can expect the pH to drop overtime and go back up after a flush, if the soil is acidic the pH will always drop fast after a flush and constantly be turning acidic, if you flush and the soil runoff goes up to say 6.5 but a week later it is back at 5.5 then this is from acidic soil and more lime should have been added to the soil to begin with.

In conclusion a pH and ppm meter are essential but do not think that they will solve your pH problem, only lime will do that as it replaces acidic hydrogen ions loosely bound to the soil particles with alkaline ions such as magnesium, calcium and potassium etc etc this is called buffereing. Adding pH6.5 water to your soil will not change the soil acidity so simply flushing acidic soil will not help as it will very quickly return to its acidic conditions.

Any questions? Peace

What would be the way to go about adding lime to a plant that's alrdy been vegging in a 5 gallon bucket for 2 months?

Up pot ? And how big if up potting is the only way? Im sure the root ball is pretty soild thru the bucket and will have a tight hold on the promix.

Best way is to mix it in with soil before planting, the finer the grade the quicker it works with a powder being the quickest, topdress it on the soil but i have no idea how much, as foe mixing it in with the soil before planting go with 1 teaspoon a litre of soil or a tablespoon per gallon of soil and go from there.

What makes you sure you have a pH problem?

5 gallons is a lot of soil. Peace

You know I wouldn't think I would have a ph issue my pens are calibrated. my routine is solid..

I know the most effective way would be to mix the lime before planting but in this case I just thought promix was fine straight from the bale.

So I know epson salt is magnesium sulfate right? I have some magnesium sulfate and magnesium chloride mix that I use for adjusting mag in my saltwater reef tank ...can I use that in replacement of epson salt?

Mgnesium chloride is magnesium and chloride, too much chloride is toxic to plants so dont risk it although some gardeners use it but most will stay away from it. Epsom salts is cheap and available, go get that.

Promix might be fine for pH striaght out of the bag, you need to ask promix growers advice on that one.

If the routine is solid then try adding the epsom salts to the plants water, think it was a teaspoon a gallon gives you 300ppm a litre which is just about right for a one off fix, maybe twice at most, if this dosent fix it then it is not mag or you are lacking in other nutrients making the extra mag unabsorbable.

Sounds like you only have small problems, try not to over complicate or overthink it. Took me a while to get use to using lime and epsom salts. I prefer to add most of it to the soil and add any extra the plant needs during the grow. Read up on it and try to find the best way that will work for your plants, lime takes a little while to work and will need watering in well to get it incorporated into the soil. Once its there expect quick results, a cal/mag problem or pH problem only take a short while to show new good growth once problem is fixed. Good luck

I recently limed my potted plants. I had a couple of inches in the pots I could add to so I waited until they needed water, made up a batch of soil and limed it really well. Topped off all the pots with it and watered well. Checked pH and it was 7ish all over the place. Still holding steady days later.

Promix is soilless so what do u think would be the ideal ph of my feeding mix/water.

I like to pH my ferts and water to between 6.5 and 7, i aim for my runoff to be at about 6.5, as i add ferts this will slowly drop until the point at which i need to flush. Too much lime can be a bad thing but it is very hard to add too much. Powder your dolomite lime to make it faster acting, should notice results straight away.

A word to the wise, it dosent really matter about pH'ing water and ferts if the soil is spot on with its pH. If you think the water will change the pH of the soil by adjusting it to the pH you want you will be mistaken, water or ferts pH'ed to 6.5 will not change the soil pH to 6.5 hence why a pH meter is not really usefull for reading runoff.

In my opinion runoff at pH7 is a little too high, maybe too much lime. Peace

i was told checking run-off was pointless, only soil and water before i use it was worth measuring...

Not pointless but not a accurate way to check pH. Soil is different to water, acidic water dosen't turn the soil acidic. Ferts will lower pH so keep an eye on runoff pH and expect it to drop when you add ferts. When it drops too low you need to flush. Regaurdless of the soil or runoff pH the only thing you can do if you suspect acidic soil is to add lime. Runoff is complimented by ppm or an ec meter. When there is a lot of salts in the soil the runoff ppm will be high and pH low, hence you know when to flush. Peace

If after you have raised your pH from flushing and the runoff quickly turns acidic again then you probably have acidic soil, not because of the ferts, thats salt buildup and different. Peace

well its a learning curve thats for sure, im going to buy the bits i need this weekend online and they should all be here by the time ive watered a couple more times....hopefully.

how about the distilled white vingear ? do y all use to low PH ? i learned it from Jorge Cervantes in his book. he said table spoon of distilled white vingear per gallon and it will make ph more stable plus use soil master as well....man, Jorge is legendary, he know his stuff real good peace

Vinegar will not change the properties of the soil! It will only alter the water that the soil holds, please understand that only things like lime will buffer the soil pH, yer you can make the runoff look good but dont mean a dam thing if the soil is acidic.

Jorge is talking bO!!ocks here!lol! Peace

ShowMeTheSmoke said:

Promix is soilless so what do u think would be the ideal ph of my feeding mix/water.

Click to expand...

ProMix is peat based and acidic. I make my own mix, but the peat moss I use comes from the same people that make ProMix (Premier).

Use 2tbl/gallon of mix, or 1cup/cf of mix, of Dolomite Lime. Best added to the mix before use, but you can do a top dress. Powdered/Ground/Pulverized is best, but the pellets will work also. I use both.

If you can't find dolomite, garden lime (calcitic), or agricultural lime will work also. NOT hydrated or slaked or 'quick' lime. These are to be avoided as all have been treated in one way or another. What you want is just ground limestone.

For your 5 gallon buckets, apply 10tbl of the lime and water it in.

*I* don't pH anything and haven't for well over a year. No need with a well limed mix.

~$5 for a 40lb bag at Lowes or HD.

Wet

Wetdog said:

ProMix is peat based and acidic. I make my own mix, but the peat moss I use comes from the same people that make ProMix (Premier).

Use 2tbl/gallon of mix, or 1cup/cf of mix, of Dolomite Lime. Best added to the mix before use, but you can do a top dress. Powdered/Ground/Pulverized is best, but the pellets will work also. I use both.

If you can't find dolomite, garden lime (calcitic), or agricultural lime will work also. NOT hydrated or slaked or 'quick' lime. These are to be avoided as all have been treated in one way or another. What you want is just ground limestone.

For your 5 gallon buckets, apply 10tbl of the lime and water it in.

*I* don't pH anything and haven't for well over a year. No need with a well limed mix.

~$5 for a 40lb bag at Lowes or HD.

Wet

Click to expand...

nice post, i see so many people using Pro-mix straight and thinking its ok.....
it says it is buffered to a ph of 5.8-6.2 so it might work for the first week, until you feed acidic nutrients.
PS, ShowMeTheSmoke 1 cubic foot is 7 gallons, or 1 and a half 5gal buckets.
if you want some longer lasting PH buffers look into Crushed Oyster Shell, its sold as animal feed and is dirt cheap.

iNFID3L said:

hi people, ive had a bit of an mg def going on with one of my plants, so i add some epson salt, correct dosage has been mixed with water with no nutes, the water p.h was bang on 7.

has anyone got anyidea how long it might be before i start to see an effect ?

Click to expand...

i dont know for sure, but an educated guess is a week or two. no dispespect to other guys here but i'm only lamenting my own observations in my own grow op and everyone's is a little different. lemme know if i was right. also i add 1tsp/gal epsom salts and water with this addition about every third week. seems to help. i use straight tap water, which i dont measure it's ph and it's generally pretty helpful to plant growth. when i have time i will have my tap water analysed for ph, heavy meatals, and whatever else is important to maintain overall good health.

So the pro-mix seems like the problem and top-dresseing powdered lime or those pellets seems like the answer, at least this is some sound advice on pro mix people have given, its pH dosent seem good and yes it seems you need lime and perlite to amend the soil from the bag. Peace

Kingrow1 said:

So the pro-mix seems like the problem and top-dresseing powdered lime or those pellets seems like the answer, at least this is some sound advice on pro mix people have given, its pH dosent seem good and yes it seems you need lime and perlite to amend the soil from the bag. Peace

Click to expand...

when i gardened for customers years ago, for containers grown outdoors i always used pro mix with a little composted manure for N and i think it may have changed ph by it's nature being acid, right, idk...i'm just assuming without doing any due dilagence but hey im high so ill live wit it

All my soils are peat based, at best 60 percent and definatly need lime. I assume most soils need lime but good drainage and organic ferts reduce the acidic effect as well, eventually the soil will turn acidic without lime though.

Regular repotting helps as well but i feel that any grower should be aware of needing lime, it is a simple amendment, would have thought with a name like pro-mix it would be amended already. Peace