Rock Phosphate too slow for indoor gardening?

[SeaMaiden]

I used a relatively inexpensive aquarium test kit that's known in the trade for its reliability and relative accuracy. It's a colorimetric, liquid drop kit, some tests are titration test, but they're really easy to perform. The kit is about $25. The hardness tests are simply for general (GH) and carbonate (dKH, aka German degrees of hardness) types, they don't get any more specific than that. If your well is shallow it's likely also greatly affected by rains or lack thereof. I definitely notice changes with ours, and we have to replace filters frequently when there's more rain.

My well is deep, almost 800' deep, the water is COLD, definitely has both general and carbonate hardness levels that are a pain to deal with. We also happen to live nearby a gypsum cave called Black Chasm, so I figure that between the granite, the volcanic rock, etcetera, we've got ourselves a hell of a mineral soup going on here.

In any event, the point is that the water itself can have a great effect on what ends up in it and what doesn't, how easily one may or may not shift parameters such as pH given what's in solution, yadda yadda yadda.

 

[VerdantGreen]

I'm not trying to stir the proverbial "pot" here but, I've done extensive tests with pH adjustments in liquids. I've used the EJ pH Up and Down, used guano and seaweed to change the pH in liquid solutions as well as other organic components. What seems to always happen is the pH changes again within just a few hours. I used about a cup of EJ pH just to try to keep a five gallon bucket of liquid tea stable for 24 hours.
I encourage everyone to do a little experimenting with this. It's lots of fun and quite interesting. Keep some notes.
Check the pH of some guano tea. Then check the pH of some Maxicrop liquid mixed with water as directed. Then some Neptune's Harvest fish. The pH may scare you, but our plants love it.
Don't take my word for it. Experiment.

And to reply to the OP's question... I see no reason not to add some slow release nutes like rock phosphate and greensand. Within reason of course. However, they will not supply enough N-P-K to feed your plants properly alone.

Burn1

hi Burn, i think we;ve discussed this before, and im pretty certain that our different experiences with pH and how much it matters is that you are using lovely neutral low alkalinity well water, whereas im using tapwater that has had lime added to it for 'better drinking quality'
actually ive recently switched to rainwater as ive realised that there is a considerable build up of lime in my soil during a grow... im hoping that i may be able to start recycling my soil now.

i still use a bit of citric acid though becuase of its ability to keep P available in the soil. otherwise it can get tied up pretty quickly

also we should keep in mind that P isnt particularly mobile in soil - so mixing your P amendments into your soil is preferable to top-dressing

VG

 

[rrog]

VG, you figure you have active myco to supply P or no?

 

[VerdantGreen]

hi rrog, ive never bothered trying to use myco with cannabis because from everything ive read its a bit hit and miss. others would disagree im sure but ive never felt i needed it.

VG

 

[moses wellfleet]

...3 years using the same soil. It werks bro~


View Image

difficult to argue back with evidence like that

 

[187020]

Built up minerals from tap water ruined my recycling program...high ph and lockouts...

With peace

 

[rrog]

Craven, something went very wrong, then. That's not normal. In fact I've never heard of such a thing before.

EDIT: I now see that I was wrong. I'm learning.

 

[mad librettist]

if the tapwater is bad enough it can kill anything.

 

[187020]

Yup too much dissolved minerals over time had it "over-buffered"... Half tap/half RO maybe? Peace

 

[rrog]

I've got some pretty hard well water and so far, so good.

 

[h.h.]

hi rrog, ive never bothered trying to use myco with cannabis because from everything ive read its a bit hit and miss. others would disagree im sure but ive never felt i needed it.

VG

Yeah that.
I don't see the dirt cloud around mj roots like I do around other plants which leads me to believe I don't see very well, but no, it doesn't seem to have as active a rhizosphere as other plants.
This is where I think beneficial fungus needs to be included in a broader catagory.
It's that little white fuzz that appears, worrying everybody, that breaks down the hard materials. The shrooms popping up that fascinate us. Besides the Zen of it all, it's feeding the plant. It's not myco, but it is fungi and certainly deserves our attention.
One good reason to reuse soil. One good reason not to til. A good reason to top dress.
SRP with soy leaves reportedly peaked out at 60 days and dropped at something like 90. Not sure exactly, Google it. I imagine other types of leaf liter would work as well. You want something to help it along.

 

[VerdantGreen]

Built up minerals from tap water ruined my recycling program...high ph and lockouts...

With peace

same here, took me ages to work it out, i was planting other plants in the soil and they were turning yellow.

anyone who thinks high alkalinity tapwater doesnt matter should look at this thread
https://www.icmag.com/ic/showthread.php?t=231106

 

[rrog]

VG you add the acid occasionally to counter the alkaline water?

 

[VerdantGreen]

acid counters the acidity of the water and the plants grow well, but i'm pretty certain that there is too much lime build up in the soil to recycle my soil. i still use it in the garden but i tend not to use it at more than a third volume in potting mixes or otherwise the plants yellow.

i used rainwater for the whole of the last round so will see how that soil works recycled.

VG

 

[rrog]

I wasn't aware that this was an issue with recycled soil

 

[VerdantGreen]

it can be, but will depend on your water quality. bear in mind that many amendments are also liming agents. rock phosphate, bonemeal, high P guano can be too.

VG

 

[Microbeman]

acid counters the acidity of the water and the plants grow well, but i'm pretty certain that there is too much lime build up in the soil to recycle my soil. i still use it in the garden but i tend not to use it at more than a third volume in potting mixes or otherwise the plants yellow.

i used rainwater for the whole of the last round so will see how that soil works recycled.

VG

I quit using lime altogether once it was added in minor amounts in the original mix.

 

[rrog]

MM do you acidify the soil in some fashion? Do you expect P to be significantly supplied my myco or only to a minor degree? I would think the opportunity for serious myco relationships would come from no-till. Third grow in amended no-till seems like it would have fabulous fungal network plugged in and rocking. Like the Captain is benefiting from.

 

[growingcrazy]

Yup too much dissolved minerals over time had it "over-buffered"... Half tap/half RO maybe? Peace

How long did it take these problems to show? Soil life and cycle wise?

I have been running a no drain soil bed for about 3 years with very hard water. I haven't run into any problems, yet. That is why I am curious on the time frame.

 

[187020]

It took a year of recycling to become a problem...I still have the dirt, trying to figure how to rinse it! Maybe put it out in the rain? Peace