Osmocote is it safe? - Page 3 - The Planted Tank Forum
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post #31 of 39 (permalink) Old 05-09-2019, 02:09 AM
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If you bought it for aquarium use, then perhaps it came in gel caps, but if you buy it in the retail package, it's just the beads. The beads are reportedly small porous ceramic balls with the fertilizer mixed in. The water is able to leach the fertilizer out slowly over time. Whether or not it's truly osmosis, I don't know, but I'm sure that's where the name comes from. It's normally used in terrestrial plants, mixed into the soil, and I believe the package suggests it will leach out over 6 months. I've seen it in aquariums for feeding root feeder plants like crypts and swords. For vacation feeding, and feeding in general, I would pick up one of the $40 programmable dosers. You calibrate it and connect it to bottles of your fertilizer and every day it puts the correct amount in the tank. I wasn't good at fertilizing consistently when life got busy. Since switching to auto-dosing, it has been so much better.
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post #32 of 39 (permalink) Old 05-09-2019, 02:43 AM
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Just an FYI:
For aquariums/ponds ect.. NOT available in the US..

How it works

In Water Gardens & Aquatic Plants, prills are compressed into tabs that are enclosed in a non-soluble casing to prevent water contamination
The release of fertiliser is controlled by temperature (not by moisture)
When the weather is warm in Spring, Summer and early Autumn, plants need more food and the fertiliser is released quicker
In Winter, when temperatures are lower, plants need less food because their growth rate is reduced, so fewer nutrients are released from the tabs
What "we" inc. myself, use:

Not suitable for
Do not use in hydroponic growing systems, ponds or pots submerged in water
Do not use on lawns - use only specifically named fertilisers on grassed areas
NOW here is the thing, this is how they say it works:
How it works

The release of nutrients from the fertiliser depends on soil temperature, not soil moisture
One could speculate that heat enlarges "pore sizes" so more is released (you need water though as transport) at higher temps..
Actually it is a bit complicated:

moisturE. tEmpEraturE. rElEasE.
An Osmocote Plus prill contains N-P-K, six micronutrients and
magnesium. Water vapor is absorbed into the prill through the
patented, polymer coating and dissolves the fertilizer inside.
The release of fertilizer is primarily controlled by temperature.
When it’s warmer and plants are growing more actively, the
coating expands allowing more fertilizer to be released.
When it’s colder, less fertilizer is released

"A man with a watch knows what time it is. A man with two watches is never sure."
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post #33 of 39 (permalink) Old 05-09-2019, 11:41 AM
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So Osmocote come in all different packages. Mine as described below is slow release up to 2 months and is safe for shrimp and fish.

An all-in-one solution. One application contains 11 essential nutrients and feeds up to 1 to 2 months in an aquarium. Works with virtually all plant varieties and growing conditions. Each granule is coated with a unique resin that controls nutritional release. Plants get what the need, when they need it.

This product is an excellent plant food for aquarium plants. I use 1 capsule every 16 square inches (4"x 4") in my planted tanks. The amount of fertilizer that must be used should depend on factors such as water change frequency, amount of plants in the aquarium, temperature of the aquarium, lighting, etc. I suggest starting slow and letting the plants show when to add more fertilizer. I do 20% water changes on a weekly basis and fertilize my plants once a month, like stated above, watch your plants and feed them as needed. Insert the gelatin capsules deep into the substrate of your fish tank.

These root tabs are fish and shrimp safe.

Tabs are shipped with a dessicant bag to protect them from moisture.

TOTAL NITROGEN (N)*……………….....15.0%
Ammoniacal Nitrogen………………………8.0%
Nitrate Nitrogen……………………………7.0%
SOLUBLE POTASH (K2O)……………......12.0%
Calcium*.......................................... .................1.9%
MAGNESIUM (Mg)*…………………..…..1.4%
SULFUR (S)*…………………………….....4.0%
BORON (B)*……………………………......0.02%
COPPER (Cu)*………………………….......0.05%
IRON (Fe)*……………………………...…..0.45%
Chelated Iron (Fe)*………………..………...0.03%
MANGANESE (Mn)*…………………..…..0.06%
MOLYBDENUM (Mo)*…………….………0.02%
ZINC (Zn)*…………………………..………0.05%
* The nitrogen, phosphate, potash, magnesium, sulfur, boron, iron, manganese, molybdenum, and zinc sources have been coated to provide 12.7% coated slow-release nitrogen (N), 7.6% coated slow-release available phosphate (P2O5), 10.2% coated slow-release soluble potash (K2O), 1.1% coated slow-release magnesium (Mg), 5.1% coated slow-release sulfur (S), 0.015% coated slow-release boron (B), 0.35% coated slow-release iron (Fe), 0.05% coated slow-release manganese (Mn), 0.015% coated slow-release molybdenum (Mo), and 0.015% coated slow-release zinc (Zn)

Thank you for Looking9
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post #34 of 39 (permalink) Old 05-09-2019, 04:43 PM
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In my tank for the last 9 years of using them - no problem, but you gotta be careful about the dosage. in my case, 36 gallons shrimp tank - total 8 vegi capsules (4 caps at each back corner of the tank), and see how plants are doing for at least a week.
I made my own vegi capsules by filling up the osmo, but later veg capsule melted and left outer shell in the substrate - not beautiful if you are neat freak... so I pour them into some sort of small plastic capsule or container, and punch a couple of holes which water can come in/out for release.
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post #35 of 39 (permalink) Old 05-09-2019, 11:44 PM Thread Starter
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I have decided to try dynamite select, apparently its slow release, and has good reviews

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post #36 of 39 (permalink) Old 05-10-2019, 02:10 AM
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My 29 gallon is only 6 weeks old, but I haven't had any issues using the individual bead method, osmocote +. I err on the side of caution and only use it every few inches near the heavy root feeders. I noticed my foreground plants were slightly more yellow in a place I missed and within a week of adding a couple they were nice and green. I should probably add more next water change. I also dose the water column.

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post #37 of 39 (permalink) Old 05-10-2019, 03:06 AM
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Scotts Australia.. Clear as mud??
Scotts response

Hi Jeff

Unfortunately Osmocote Aquatic Plants & Water Gardens is only available in Australia, BUT this product is based on a commercial Osmocote product - Plant Tabs - which we believe would be available in the USA.

We are not aware of using Osmocote in gel caps for freshwater use but they would probably work. The gel itself would dissolve relatively slowly (depending on the type of gel used) and the coating of the Osmocote prills (beads) is also controlled or slow release. Worth thinking about.

Because we have the Osmocote cones of the Aquatic Plants & Water Gardens, we don''t have to think of alternatives!
to reiterate US:
Thank you for contacting us and for the opportunity to help you with your lawn and garden endeavors.

... unfortunately, we do not have any information on products that are sold in other countries. We also do not have information on why a product would be registered for us in some countries and not others. I do apologize for any inconvenience.

We do not recommend using Scotts Osmocate Plus in an aquarium because it is not designed for that use and the time release would be destroyed by soaking in water.

Again, thank you for taking the time to contact us and for your interest in our products. Please feel free to contact us anytime we may be of assistance.

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The Scotts Company and Subsidiaries
I give up..

Maybe just take some plain Nitrate/ammonium free water and dump a few in.. test every day..

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post #38 of 39 (permalink) Old 05-10-2019, 04:22 PM
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"We do not recommend..." is stock standard official language for "I can't tell you to use it in a way that's not explicitly written on the label for liability reasons.". I had to use that one umpteen bajillion times during my tenure with Brightwell. I'd be willing to bet the Aus answer is closer to the truth than you'll get out of any US rep.

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post #39 of 39 (permalink) Old 05-10-2019, 06:12 PM
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Ok so to sum up, we know lots of people use them. They sometimes leave the little BB sized balls over the substrate. You can put them in as the little balls or take a bunch and put them in a common gelcap which is generally easier to handle. There appears to be two varieties. One for terrestrial and another for aquatic. The aquatic is not for sale in the US. (Only confirmed in UK). These appear to have different mechanism for slow release. Aquatic is driven by heat and US is by moisture. There is a possibility of them dispensing more than expected.

So with the info on the two varieties. The question of dispensing more than expected might be tied to which kind.

I know I have used the US ones I put in gel caps. That was in moderation < 15 in a 75g with no noticeable ill effects.

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