# how long does miracle grow last?



## allaboutfish (Oct 14, 2011)

im wondering how long this lasts thanks.


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## talontsiawd (Oct 19, 2008)

I am just starting to see deficiencies in plants in my 5 gallon tank after 2 years. However, it does not have co2, nor is it really fertilized at all outside of fish. 

However, I don't want to say 2 years, even with this particular tank, with any confidence for a few reasons. First, the deficiencies are minor so I am not even sure what they are. I wouldn't likely notice if this was a new tank, it's just been a long time. 

Second, I am very sure it's not 100% depleted, if it is depleted of something, it's likely not depleted of all nutrients (I think it's a magnesium deficiency but it could be nitrogen or possibly iron, it's not bad enough for me to really tell and I haven't done anything about it). 

Lastly, their has been both feeding changes and I have been planting it more densely as it grows. Both could be a culprit and both are totally unrelated to the soil.


So 2 years for me, minimum, but then again, I don't even know that my tank needs more than fish waste/food. None of my other tanks have made it to where it has been depleted. Most were redone, 2 had issues with the soil going aerobic.

It should last a long time though.


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## BBradbury (Nov 8, 2010)

allaboutfish said:


> im wondering how long this lasts thanks.


Hello all...

Depending on how much you're able to use, the organic mixture needs to be supplemented in four to six months. Everything depends on your particular tank chemisty. I've used it for potting my aquarium plants (see attached pic) and the mixture lasts about six months. Then, I started to dose liquid "trace elements" in addition to the ferts the fish produce.

Miracle Gro is pretty good, but overrated I think, plus it can get messy if you're not careful. If it was really good, everyone would be using it.

B


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## wkndracer (Mar 14, 2009)

*opinions are like belly buttons*

Light and demand can change things but using 1-2" of MGOCPM lasts as a plant food source for a very long time. _*
MUCH*_ longer than the second reply even if used under high light, CO2 injected, high demand conditions. (Been there, done that too.)

55g, simple, unassuming tank. 
Last photo currently taken right after a trim on a Med light tank first loaded (wet) 4/3/2009.
This tank has trace dosing added with water changes (sometimes) and the water changes are not frequent. 
Fertilized by substrate and fish, fish food only. Growth slowed somewhat after about 18 months but is stable and predictable. 
Lighting, unused heater, power head and sponge only also .

I don't feel it can be "overrated" because it has worked consistently for to many people. 










mileage can vary but if issues start in only 6 months you have another problem LOL


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## allaboutfish (Oct 14, 2011)

ok cool. now what about when you freeze the miracle grow and put it under the plants? same amount?


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## Eldachleich (Jul 9, 2011)

Freeze it?
What would that do?

I don't have alot of info on this as I just got into dirted tanks, but I do have a few tanks that have been running for around 8 months with MGOPS. They have yet to show signs of any deficiency and are still going strong.
I did sprinkle some laterite at the bottom not that it makes a huge difference.


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## allaboutfish (Oct 14, 2011)

if you freeze the miracle you can add it to tanks that already have substrate.


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## AngelfishKid (Dec 7, 2010)

Mine lost its kick after 1 year. But I still get good consistent growth, just not as fast as when it started out.


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## nonconductive (Jan 29, 2010)

yea that second reply was overrated.


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## Diana (Jan 14, 2010)

Freezing it should have no effect on how long it lasts.

Soil lasts in 2 ways:
The initial load of fertilizer can get used up. Then all you need to do is add more fertilizer, or prevent the problem by adding fertilizer before it is all gone. Tablets under the substrate, or water column dosing are both good ways to add fertilizer to a substrate, especially if the substrate has a reasonable CEC. It will take in the fertilizer pretty well, and keep it available for the plants. This is already going on with fish food, but in a high tech tank the plants probably need more fertilizer than just fish food. So, when the additional fertilizer in the original substrate is gone, you need to add more fertilizer. 

The material itself might break down. The organic matter part will decompose. The sand/soil part lasts forever (in aquarium years). There is not much you can do about this (organic matter decomposing), except re-do the tank, perhaps adding some compost or peat moss to the remaining soil. Sure, add some compost or peat moss by freezing it (so it won't go all over the tank while you are placing it under the substrate). Saves having to completely redo the tank.


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