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Making My Own Planted Tank Fertilizer

2K views 15 replies 4 participants last post by  thedood 
#1 · (Edited)
I've been fertilizing outside of my aquariums, as well as lightly fertilizing in them, for the past couple of years. I rotate crops from the fertilizer into my fish tanks, where I use a simple fertilizer like Leaf Zone or Aqueon Plant Food a couple times a month. I do this because it keeps down on algae, fish and plant toxicity, and chemical instabilities. I do this because I have no 'planted' plants. Instead I stick with floating plants or those that can be weighed down and sit on top of a coir mat substrate fashioned into hills and valleys for interest.
https://aquariumexperiments.com/2016/04/25/i-hear-a-harp-angels-singing-when-i-look-at-this-tank/
I've also been doing this because it's taken me this long to gather enough information in order to make the right choices and hopefully not kill anything.

So here is what I have so far:

As of today I have added:

  1. Minuscule Amount of FeEDDHA (I need to get a mg scale to know exactly how much. I stir in a pinch a little bigger than the tip of a ball point pen. The water turns slightly tannin colored.)
  2. 1/2 tsp of each to the 10g’s. 1.5tsp and 2 tsp each in 29g and 55g.

  • epsom salt
  • potash
  • Calcium Nitrate - I think this killed some fish, so I will cut the dose by quite a bit.

pH has remained at 6.6 - 6.8. @76 degrees F

The coir in my tanks can bind up calcium. Since I live in a soft water, low GH area, adding calcium should be a good call. I don’t think adding calcium in hard water areas would be necessary in most cases, but maybe? I’ve noticed that many of the aquatic plant foods have little or no calcium. It probably needs to be considered for some of us.


*I believe potassium nitrate would be the right choice for those with harder water.


So as of today, I’ve added epsom salt(magnesium sulfate) and potash(Potassium Chloride) with the Ca(NO3)2. I added them all dry and just swished the water around. I played with the Ca(NO3)2 in a jar of water first, to see how quickly it dissolves. I believe the water got a little warm while it dissolved. Then I looked further and found it does have a thermal reaction. Interesting.

Pictures from Today:









 
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#2 ·
  • epsom salt
  • potash
  • Calcium Nitrate

The coir in my tanks can bind up calcium. Since I live in a soft water, low GH area, adding calcium should be a good call. I don’t think adding calcium in hard water areas would be necessary in most cases, but maybe? I’ve noticed that many of the aquatic plant foods have little or no calcium. It probably needs to be considered for some of us.


*I believe potassium nitrate would be the right choice for those with harder water.


So as of today, I’ve added epsom salt(magnesium sulfate) and potash(Potassium Chloride) with the Ca(NO3)2. I added them all dry and just swished the water around.
MgSO4 (epsom salt) will increase GH.

To raise potassium most will use K2SO4.

CaSO4 is typical for raising calcium/KH levels, it dissolves well.
CaCO3 can be used but does not dissolve well.

I imagine calcium nitrate and/or potassium nitrate are fine if your tank does not accumulate NO3 due to a high fish load.

I am guilty of overstocking due to these crazy breeding fish.
Nitrate free mixes for me.
 
#4 ·
Yes! Finding balance. It feels like I'm trying to hit a moving target. I've only recently become confident enough that I can hold a tank in a simple balance without too many variables. Now I'm adding more variables. It's scary, but fun at the same time.
 
#3 ·
MgSO4 (epsom salt) will increase GH. If the tank needs magnesium, this is a good source.

To raise potassium most will use K2SO4. Many raise both NO3 and K with KNO3. If your tank does not need the NO3, then K2SO4 is a good source of K.

CaSO4 is typical for raising calcium/KH levels, it dissolves well. This does not raise KH levels. It will raise GH, it is a good source of Ca.

CaCO3 can be used but does not dissolve well. This will raise GH and KH. Often used in the form of coral sand or similar, and used as a substrate, or added to the filter.

I imagine calcium nitrate and/or potassium nitrate are fine if your tank does not accumulate NO3 due to a high fish load. This is true.

Adding Ca or Mg supplements to a tank that already has a good GH for the livestock may not be needed. When in doubt find out the actual levels of Ca and Mg, then dose one or the other if needed. Aim for a ratio of Ca:Mg of 4:1. It does not have to be exactly this ratio, but something close.
There are other sources of fertilizers. Most are combinations. If your tank needs all the elements these will add, then use that one. If your tank does not need some, then choose something else.
 
#5 · (Edited)
5/2/16

The algae has quickly begun growing on 29g tank sides and coir in one day of using these ferts. The only tank algae is not growing in today is the 55g with a 24watt Green Killing Machine. Gotta love UV.

This also happens when I add the recommended amount of Leaf Zone or Aqueon Plant Food. The day after I can see a little algae on the walls. But it doesn't get very far over a week or two before I clean it out with the diatom filter. I think I'm seeing much more algae on the walls in one day with this formula. Maybe I should dial back something? I'm thinking the calcium nitrate may need to be either eliminated or lessened. But I wanted to see if using it will help absorption of the iron so that the tank clears of the tannin effect more quickly. I believe in just one day of using the Calcium nitrate the iron color has lessened. ...but the algae has grown. Ha! '...find balance, Grasshopper...' (Kung Fu)

Day 2 Pics:
https://aquariumexperiments.com/2016/05/02/day-2-of-diy-fertilization/
 
#7 ·
Ha! '...find balance, Grasshopper...' (Kung Fu)
David Carradine has passed and so have some fish!
In a few episodes he was hit with a stick(bamboo).:laugh2:

They say NO3 is a slow killer of live stock.
Quicker if dosed all at once maybe.

Sorry you lost some fish in all this.
Maybe stick with proven compounds and I'd change some more water.
 
#6 · (Edited)
Two Corys Dead Second Day

Ok, so I killed some fish. All others fine for now. Rummy nose, white clouds, bettas, gouramis, otos ...and one lonely cory that doesn't look happy. I'm thinking this was the calcium nitrate. I don't have a nitrate test, so I'm off to buy one. This was in the 55 gallon. I will make sure to lower the amount by quite a bit next time, if I add any at all.

The cory's were breathing hard before they kicked the bucket. I did water changes.
 
#9 ·
Best way to deal with this whole question is a sort of question and answer sessoion.

1) What do your plants need?
Over a dozen elements.

2) What are supplied in other ways, not fertilizer?
O, H, (from water)
C, (by adding CO2 or Excel)
Ca, Mg (If the GH of your water is at least 3 German degrees of hardness there is probably enough.)
N, P, most traces (fish food). Test the NO3, if fish food is supplying enough N, then it is also supplying enough P and most traces.

3) What is left to be supplied as fertilizers?
Ca, Mg, if your tap water is too soft. (low GH)
N, P, most traces (If fish food does not supply enough.)
K, Fe, These are low in fish food, and most water does not have much. These are the first 2 I would start adding.

4) How much?
This is a big question.
 
#10 ·
Calcium nitrate is dosed for planted tanks that have soft water/low GH. It is that I have dosed too much, I believe. The nitrates were 40 - 80 ppms. With water changes I am down to 10 ppms. So lesson learned: Dial the Calcium Nitrate way back.
 
#11 ·
5-3-2016 Lost Two More Fish

So I've lost four fish total now. A few more are looking bad. I really screwed up with the nitrate. So I've been doing water changes for the past 24 hours.

On a side note, the water feels really silky. I'm sure there is a word for that 'Calgon, take me away' bubble bath feeling.
 
#12 · (Edited)
5/4/2016 - See Algae on 55g w/UV

Today I'm seeing algae grow on all of my plants in the 55g. The UV has kept the algae out of the water column, but it is growing on the plants. I hate nitrates.

So the good news is, I have learned that I added too much nitrate. I can easily break the tanks down, pull the coir and plants out, do another water change, and start all over again.

The bad news is, I blew up some fish. The second big mistake is 'dry dosing'. I think my piggish bettas ate some of the crystals before my swirling them made them dissolve completely. So the honest truth is their bellies 'exploded', and their bodies bent, nose up into almost a V. Sad. UPDATE: I think these Bettas that 'blew up', are dying from being full of eggs, and not absorbing them properly. Another female betta has died the same way, but was not in the tank with ferts. All were very very full of eggs. I'll have to look into this.

Rummy's, white clouds, gouramis, otos, many other bettas, and one lonely cory are the sole survivors of my latest experiment with fertilizers. But I'm not giving up on making my own ferts. I know I can get this right. It would be nice to feel comfortable fertilizing my tanks without worry of algae, lack of nutrient, etc. But I have a feeling it can never be perfect, because the target will always be moving. So it's better to err on the side of too few nutrients, than too many. I can understand why the ferts that are made for aquariums, are indeed MADE FOR AQUARIUMS. Attempting to give the plants the amount of nutrient they need, but still adding typically less than they need so you don't harm livestock, is the issue. How do we get the nutrients to the plants in high enough doses, that we don't cause algae blooms and livestock harm?

CO2 is probably the way to do it. I've read where adding co2 liquid (soda w/o salts) to terrestrial plants helps them absorb nutrients at a higher rate. If this is true, then adding fewer ferts but more often with a co2 system may be the ultimate growing medium in the aquarium.

I'm not going the CO2 route for now, so instead of adding enough ferts weekly, I'll add miniscule amounts of ferts daily when I feed.

Over the next couple of weeks I'll make a liquid of those four (Fe (fully chelated), KCl, NO3, MgSO4). I may leave out the calcium nitrate, but I still think I need calcium so I'm not sure. This will be my PMDD (poor mans dosing drops).

For now the plants looks so green/red and healthy. Fish, some not so good.
 
#15 · (Edited)
May 30, 2016

I've continued to use the fertilizers weekly; (Fe (fully chelated), KCl, NO3, MgSO4), except for the Calcium Nitrate. I have added 1/4 teaspoon Triple Super Phosphate 0-47-0 to the 55g this week. It cannot be added at the same time as the other ferts because it will precipitate into a milky substance. But I now have what I call 'phosphorus roots'. Fuzzy roots on my Frogbit. The hair algae is always on the peace lily leaves and creeping jenny, so not from the addition of phosphorus. I have not noticed a spike in algae (yet) from the single dose of PO4. But these roots are awesome!





The Dwarf Lily is growing big strong leaves, still not as red as I would like. But the Gouramis decided the Creeping Jenny was food. Although some died off acclimating submersed. So there is less. I also pulled out the water lettuce because...wow...it started growing over the frogbit in thick mats. So now I only have frogbit in these tanks.




 
#16 ·
AWolf I admire your dedication to experimentation and willingness to avoid the status quo.
 
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