Aquatic Plant Forum banner
1 - 19 of 19 Posts

·
Registered
Joined
·
223 Posts
Discussion Starter · #1 ·
I'm wondering for those who have low tech tanks, how do you provide the plants with nutrients like potassium, magnesium, iron etc...
 

·
Registered
Joined
·
223 Posts
Discussion Starter · #4 ·
I was wondering other than getting those ferts at a lfs, are there anyother way of getting those nutrients? I know the dosing schedule.

I.E. I think baked potatoe and raisin contains potassium can I grind those up to provide plants with potassium?
 

·
Premium Member
Joined
·
4,877 Posts
I was wondering other than getting those ferts at a lfs, are there anyother way of getting those nutrients? I know the dosing schedule.

I.E. I think baked potatoe and raisin contains potassium can I grind those up to provide plants with potassium?
The problem with that would be all the organic matter in the foods decaying. It would wreak havoc on your tank. Mineral soil (yard dirt) will more-often-than-not have enough nutrients to last you for a long while with the possible exception of potassium. There is an article on mineralized topsoil in the library (look up at the gold menu-bar on the top of the page). If you use soil from your yard/garden you don't need to go through all the wetting/drying steps, but then you must be VERY careful about whether or not you are introducing pesticides or other chemicals into your tank.

I did a modified version of that method and have had good results, but I also add supplemental ferts. (I've got 1/4" clay-loam from my yard underneath 3" of inert substrate. )

-Dave
 

·
Registered
Joined
·
2,195 Posts
Plants do not use large organic molecules as fertilizer. The raisins etc would decompose, and not add much to the tank, except mess.

Get ferts here:
www.aquariumfertilizers.com

When my tanks did not need very much fertilizer, the only things they showed deficiency in were Potassium and Iron.

You could also get some root tablets, and sink them deep in the substrate near the plants.
 

·
Super Moderator
Joined
·
2,787 Posts
I'm wondering for those who have low tech tanks, how do you provide the plants with nutrients like potassium, magnesium, iron etc...
Dear Qwertus,

Sorry that I didn't answer your question earlier. Please ignore all the website advice about chemical and fertilizer sources. These are mainly for High-Tech hobbyists that inject CO2.

NPTs (Natural Planted Tanks) generally do not need chemicals. If you have decently hard water (GH greater than 4-6), it will naturally contain plenty of magnesium and potassium for plants (my book, pp. 85, 86). If you have a soil substrate, it will contain enough iron for rooted plants (my book, p. 83). [Soil contains an huge reservoir of iron AND the iron is in the un-oxidized form that plants can use.]

Finally, fishfood contains all nutrients that plants need, so fishfood additions to the tank will gradually replenish the nutrients that plants remove from the soil and water.

Unless your tapwater is extremely soft (GH less than 2), there's no need to worry about plant nutrients.
 

·
Registered
Joined
·
223 Posts
Discussion Starter · #8 ·
I checked GH earlier and it says 75 is that really soft or is it ok? some plants have some decaying spots on leaves thats why i'm trying to add some more nutrients in. I think its potassium thats lacking.
 

·
Registered
Joined
·
189 Posts
I checked GH earlier and it says 75 is that really soft or is it ok? some plants have some decaying spots on leaves thats why i'm trying to add some more nutrients in. I think its potassium thats lacking.
I'd be the last person to pretend to understand the subtle relationships which occur between GH, KH, ph, etc., but I'm thinking 75 ppm is probably too low. I do know that our tap water is very soft and if I don't occasionally add some Calcium, Magnesium, and Potassium salts, I also get holes in the plant leaves, very slow growth, and some plants like Valisneria just dissolve. These are nutrients plants absolutely need, and they prefer to take them directly from the water. The rest like iron come from the soil.

I have plain old top soil I got from Lowes for $1.49 per bag and get great plant growth. I figure if our water wasn't so soft, I wouldn't have to fertilize anything above and beyond just adding fish food.

Hope this helps,
Jim
 

·
Registered
Joined
·
291 Posts
Q: I have added Potassium. Sometimes plants will show holes in the leaves from K deficiency. There is a thread here from Diana about using 'Salt Substitute' I used the "No Salt" brand from the grocery because it's mainly Potassium Chloride. I don't remember how much was advised in the thread (originally intended for someone reconstituting Reverse Osmosis water, or starting from zero). I have a 75g tank and I added about 1/8 tsp to 2 qts of water and stirred it until it dissolved. Then I added twice the recommended dechlorinator, (enough for a gallon of water), then I added this into the tank. I did it when I topped off to compensate for evaporation. I wasn't making a water change. I figure I'll add a pinch with water changes once in a while or if I see holes in my Hygro leaves again.
For your soft water, you could follow the directions on the dosing sticky on the main NPT page, at the top, if you want to bring it up with chemistry. Adding some crushed coral, sea shell or egg shell is a good solution, too and can help keep your tank stable. You can push it into the substrate if you don't want to look at it. I think that if your GH is 75ppm, then you have about 4.5 German degrees of hardness. Maybe someone can confirm this, the divisor is about 17 for Ca and Mg? You could just add shell.
 

·
Registered
Joined
·
458 Posts
I have softwater too.
I add eggshells to the big tank.

Interesting is that I also use the plain top soil from Lowes (red bag).
The 2.5g tank had good growth for a year but the vals definitely had a problem later.
Now that my 20g long is just over 1 year I'm finding holes in my Amazon Sword.

I think I'll have to dose with some fertilizer.
It there a nice liquid one for Mg and K.
I will probably order some heaters and food from Drsmith and would like to combine the order.

Definitely something up with that Lowes soil.
 

·
Registered
Joined
·
38 Posts
I think that if your GH is 75ppm, then you have about 4.5 German degrees of hardness. Maybe someone can confirm this, the divisor is about 17 for Ca and Mg?
my aquarium chemistry handbook states that
1ppm CaCO3 results in 0.056 deg. German total hardness (°dGH)

so the divisor is more 18 than 17
regards
 

·
Super Moderator
Joined
·
2,787 Posts
You're getting some good advice from the last few letters. Thanks guys!

The 75 you mentioned is probably water hardness expressed by water treatment plants as ppm CaCO3 (it is not GH). If this be the case, your water is fairly soft (my book, p. 185) and may need a little more calcium, magnesium, potassium, and bicarbonates.

I would follow the advice given to you for adding the first 3 chemicals. Remember that calcium may be the most important one. Plants can substitute sodium for some of their potassium requirements, so a lack of potassium is not going to kill your plants.

However, plants will die if there isn't enough water calcium (my book, p. 114).
 

·
Registered
Joined
·
38 Posts
I would translate this to a GH of 5.5 (degrees) and a KH of little more than four.
In Germany this relates to a water mostly resulting from washed out limestone and probably very low on Mg.
Eggshell, afaik, doesn't help with Mg and it isn't neccesary with your GH/KH levels. At least not on short terms.
Watch the pH from time to time!
Kalium may be low or not, don't know.
regards
 

·
Super Moderator
Joined
·
2,787 Posts
The 20g-long has a GH of 100ppm, KH of 90ppm and a PH of 7.4.
The kit says the GH is moderately hard, but Diana's book says that is soft.
Either I need to add more eggshell or go straight to a K, Mg dosing.
I never could find a fixed definition of what is "Hardwater" and what is "Softwater".

At 100 ppm CaCO3, your water is probably just fine. [It is the Portland Oregon hobbyists with city water of 6.3 ppm CaCO3 hardness that need to be concerned.] That said, you could play around with a few additions.

However, adding a little extra fishfood may be the easiest way to get results. It will definitely replenish all 3 nutrients in a gradual and natural way (my book, p. 80).
 

·
Registered
Joined
·
458 Posts
Thanks for the info.
The GH and KH exist only because I put crush eggshell in at about 1/8 teaspoon every 1-3 weeks.
I usually look at the ramhorn snails and see how the shells are doing.
I feed quite a bit, to the point I have slighting cloudy water (not too much). The snails have a great time as do the shrimp.

Interestingly enough I did a rough calculation of my food input into my 20g-long and I think I'm putting in about half the quantity you were for you 50g tank on page 80.
Again this is a rough estimate.

I'm going to try to boost up the CaCO3 to gain maybe a 20ppm. I had higher ppm 6 months ago and didn't see any issue.

Another question, would brine shrimp add some of the other minerals like K and Mg.

Thanks

For the 2.5g, I've tried some over feeding but it's hit and miss. Most likely the tank is a little too cold and I'll have to buy a small heater.
 

·
Super Moderator
Joined
·
2,787 Posts
Thanks for the info.
Another question, would brine shrimp add some of the other minerals like K and Mg.
It sounds like your tanks are doing fine and you're doing the right things.

If you turn to page 79 in my book, there's an elemental analysis of brine shrimp (Table V-2). Live Brine Shrimp have 13,000 mg of K/kg dry wt and 1,500 mg Mg/kg dry wt.

All living things (plants, animals, bacteria, etc) basically contain the same chemicals. Brine shrimp are no different. That's why you can count on any fishfood to feed plants.
 
1 - 19 of 19 Posts
Top