Im just looking in to this as I also have isues with low soil PH ...
I water with 6,5 or so (light green) runn off is normaly 6 (yellow) but lately it have been in the 5ish (oranges)
3 weeks in to flowering I may add ..
and useing a GH drop test kit so Im not 110% on PH levels .. but enough to notice it drop so made a soil test ..
same type of test just for soil and yea .. in the 5ish .. maybe high 5
(5,5-5,9)
but still to low with 4 weeks and lots of nutriens left in my 7 gallon pots ..
specialy one plant do show signs (curling leaves)
so got some Maerl to day (from Plagron)
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A popular product in the Plagron range is the Plagron Maerl. This tried-and-tested natural soil conditioner is extracted from coral reefs in the Atlantic Ocean. Plagron Maerl (algae calcium) is rich in magnesium and trace elements and has an extremely high acid binding value. Plagron Maerl offers plants an abundance of essential minerals. The acid binding value is extremely high. Plagron Maerl is ideal for soils with an excessively low pH value. A correct pH level in the soil ensures that the nutrients in the soil can be maximally absorbed by the plants.. Plagron Maerl contains: carbonic acid magnesium calcium, acid binding value 54% and 9% magnesium oxide, soluble in mineral acid.
The dosage of Plagron Maerl depends on the type of plant and the pH value of the soil.
Usage in full soil: 5 to 12 kg per 100 square metres.
Usage in potting soil: 250 to 500 grams per 1000 litres, depending on the plant being grown and the acidity level of the potting soil.
18$ or so at my local grow/hydro store ..
was looking for
Dolomite lime as I read about that evrywher ..
but did`t have that ...had this insted .. nice sales person said he use it and its about the same just from another source ..
so now Im looking in to it to see what exatly it is and how much to use aso.
so I just found this "old" thread .. guess somebody els will look for this info aswell .. and since it seems to be impossible to find any info on this product or any other reef coral lime ...
I was thinking to make some
will add it on top of my soil (only way for me in my 7 gallon pots 3½ week in to flowering)
from what I can read and with my limit mat skills .. I schould use 25-50 grams per 100 liters of soil ..
I got 27L pots .. maybe with 25 liters in them ..
I will try in the low ranges fist and see what happen .. so 25 grams per 100L = +6 gram in my 25L
after "shaking it all over my soild I water with normal 6,5PH water (with a low ½ strengs nuts solution .. my plants are hungry)
a pics of my small bud leaves:
notice the curling .. hopeing the new grow will look more normal now when/if I get my PH up in the 6ish ..
I will update this with more info and pics ..