I have some old Plantabbs but it says they will change my PH. I'd like to give my plants a boost but don't want to stress the fish by changing the chemistry too much.
Is there a fertilizer that won't mess with PH?
- Thread starter Pheintz
- Start date
using powdered dry ferts will not affect pH. Flourish's line of fertilizers also do not affect pH. I use both with no problems 
Pheintz said:
Pheintz, thanks for asking that question as it interests me as well.
What in fertilizers actually affects the pH?
But more important for me is gH (hardness). Since fertilizers have Iron AND that counts against total hardness (my electronic gH tester can't differentiate against iron and I suspect less Iron has more influence on gH readings than calcium/magnesium at the same PPM proportion), I'm wondering just how much of an influence my fert is on gH.
I would imagine over time the levels of Iron would increase within the tank so that after many partial water changes, it would be concentrated...
Allow me to back up! I do RO/DI water and must treat my water to restore what I took out. That involves testing gH and adding elements until I reach my desired gH target. If over time I have a concentration of Iron in the tank, I'd not need to add as much KENT RO RIGHT (for example) to attain my target gH level. I assume this is bad for my tank (my fish anyway).
So I suppose I should really be asking:
1) How much influence does Iron have in my tank?
2) Should I ignore Iron when working towards my gH target?
3) How fast is Iron consumed by my plants (assuming in a well planted tank)?
4) Is there a good possibility I might have an Iron build up?
5) Is Iron a good gH substitute for calcium/magnesium?
Basic chemistry - go find & review.
Until you've had time to do that, know that pH swings are a function of what you add to the tank vs. the tank's buffering capacity.
If you add a little phosphoric acid to a tank that has seen nothing but RO/DI and a week's worth of poop from one danio, you should expect a big pH drop. In an established tank that has seen a fair amount of stuff added over time, you'll have some excess PO4 anions from ferts and natural sources in there, little to no pH change when there's common ion effect (buffering capacity) in play. To see how this works mathematically, review some acid/base equilibria problems from your old G-Chem books or google same.
Then, if you're interested in not just winging pH control, go get accurate levels for all of your anions (phosphate, nitrate especially) and a pH reading. Do the math and try the result on a small aliquot of tank water using a measured amount of an approptiate acid or base whose concentration is well known. Keep in mind that water changes and livestock will alter your buffer capacity over time, so you'll have to repeat this routine periodically.
I know this is long winded, but the only universally corrrect answer to "Will adding X cause a big change in my pH?" is "That depends on what's already in the tank."
re: So I suppose I should really be asking:
1) How much influence does Iron have in my tank?
2) Should I ignore Iron when working towards my gH target?
3) How fast is Iron consumed by my plants (assuming in a well planted tank)?
4) Is there a good possibility I might have an Iron build up?
Iron tests spread out over a few weeks will shed some light on all of these questions.
5) Is Iron a good gH substitute for calcium/magnesium?
I'm pretty sure the answer to this one is "no".
Until you've had time to do that, know that pH swings are a function of what you add to the tank vs. the tank's buffering capacity.
If you add a little phosphoric acid to a tank that has seen nothing but RO/DI and a week's worth of poop from one danio, you should expect a big pH drop. In an established tank that has seen a fair amount of stuff added over time, you'll have some excess PO4 anions from ferts and natural sources in there, little to no pH change when there's common ion effect (buffering capacity) in play. To see how this works mathematically, review some acid/base equilibria problems from your old G-Chem books or google same.
Then, if you're interested in not just winging pH control, go get accurate levels for all of your anions (phosphate, nitrate especially) and a pH reading. Do the math and try the result on a small aliquot of tank water using a measured amount of an approptiate acid or base whose concentration is well known. Keep in mind that water changes and livestock will alter your buffer capacity over time, so you'll have to repeat this routine periodically.
I know this is long winded, but the only universally corrrect answer to "Will adding X cause a big change in my pH?" is "That depends on what's already in the tank."
re: So I suppose I should really be asking:
1) How much influence does Iron have in my tank?
2) Should I ignore Iron when working towards my gH target?
3) How fast is Iron consumed by my plants (assuming in a well planted tank)?
4) Is there a good possibility I might have an Iron build up?
Iron tests spread out over a few weeks will shed some light on all of these questions.
5) Is Iron a good gH substitute for calcium/magnesium?
I'm pretty sure the answer to this one is "no".
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The goal is to aid those who are sick of guessing at how much of what will change their pH... just a direction pointer.
Thanks, Paula.
Is Flourish something I will find at the LFS or am I more likely to find it at a garden center? The LFSs around here don't seem to carry much in the way of aquatic plant care.
My dGh is 4 and my PH is 7.2 out of the tap. Just the other day I checked my readings and ammonia, nitrite, and nitrate are all 0 and my PH had dropped to 6.8. I am thinking the plants are using all the nitrates and I do occationally get slightly cloudy water as a result (phosphates?). I have alot of large Java fern, an Aponogeton that grows so fast it's scary, a Cryptochoryne that continually seems to grow and then turn brown and die off (had it for years and it always manages to come back. lol), and a plant with red arrowhead shaped leaves that I haven't positively identified yet but seems to be doing ok (it was a bulb). I also have several of those bulbs you get from Walmart and Petco still waiting to sprout. I am thinking the 3 medium size pieces of driftwood I have in there probably caused the ph drop.
I am using the standard flourescent lighting that came with the new hood so have been trying to stick with plants that don't need alot of light. Have not seen any major algae yet (just a little forming on the fake plants) and what little I have seen the algae consuming fish seem to be taking care of. It is usually that ugly brown slimy stuff, too.
I had considered just dosing with some nitrate but thought a regular fertilizer might be better.
Is Flourish something I will find at the LFS or am I more likely to find it at a garden center? The LFSs around here don't seem to carry much in the way of aquatic plant care.
My dGh is 4 and my PH is 7.2 out of the tap. Just the other day I checked my readings and ammonia, nitrite, and nitrate are all 0 and my PH had dropped to 6.8. I am thinking the plants are using all the nitrates and I do occationally get slightly cloudy water as a result (phosphates?). I have alot of large Java fern, an Aponogeton that grows so fast it's scary, a Cryptochoryne that continually seems to grow and then turn brown and die off (had it for years and it always manages to come back. lol), and a plant with red arrowhead shaped leaves that I haven't positively identified yet but seems to be doing ok (it was a bulb). I also have several of those bulbs you get from Walmart and Petco still waiting to sprout. I am thinking the 3 medium size pieces of driftwood I have in there probably caused the ph drop.
I am using the standard flourescent lighting that came with the new hood so have been trying to stick with plants that don't need alot of light. Have not seen any major algae yet (just a little forming on the fake plants) and what little I have seen the algae consuming fish seem to be taking care of. It is usually that ugly brown slimy stuff, too.
I had considered just dosing with some nitrate but thought a regular fertilizer might be better.