Cannot figure this out!

[OmidNiav]

Hi everyone, (long post)
It's that simple: I can't figure this out! This is a 120p tank (~70 gallons) that I setup early November 2024. All plants were pulled from the tank, all aquasoil was removed and black diamond blasting "sand" was placed. Prior to this change plants were doing ok but not at their peak due to my being short on time to do more proper maintenance.

After the switch to the sand substrate, I have noticed that the plants were still not growing well and many had lower stem necrosis. That has subsided some now (almost 4 months later) but still not at the point of me being satisfied.

Here are the parameters:

• ~65 gallons of water
• 2 aquael 2000 canisters
• Substrate is black diamond blasting sand about 3.5 inches in the front and 5 inches in the back (too deep?)
• 2 chihiros 90cm lights, 8hrs photoperiod, lights are at RGB 85%-65%-55%
• Current dosing 10-3-20 after WC (once a week) and then 10-1-5 mid-week (macros were increased about 3-4 weeks ago )
• Micros: less than half strength of @Burr740 using his product (I dose micros daily, so basically weekly dose divided into 7 doses)
  • Why less that recommended: trying to figure out if a change from higher micros to lower would make any difference in the situation
• Fe separately dosed weekly aiming 0.3 (in addition to what micro doses would add)
• CO2 injected through an inline diffuser. Don't know how much pH drop I'm getting but look at the video of the bubble counter. I think I should have a decent amount of carbon in the water
• CA 35ppm, Mg 10ppm
• KH pretty much zero

Plants that do well:

• Myrio roraima
• Limno wilsonii
• Limno barteri
• Kochi making a come back with higher ferts
• Macrandra was a recent addition, it is ok
• Murdannia engelsii doing better with more ferts
• Ludwigia polycarpa doing better with more ferts
• Iguazu red is fine
• Tricolor lotus doing good but loses some leaves from time to time
• Acorus gramineus is doing better overall
• The one seed of ottellia ulvifolia that I could germinate is doing great
• Ammania ped golden doing ok(surprisingly)
• Blood vomit is ok

Plants that are miserable:

• Eicchornia diversifolia (this is an easy plant but only new leaves are green and the rest gradually get dark. There is ample PO4 and light for it)
• Rotala maka red (wallichii type) looks burnt most of the time and less than half the stems look like are doing well
• Hygro auriculata is another easy one that is not doing well!
• Stauro purple is unhappy
• Stauro (forgot name) is unhappy
• Lagenandra meeboldii is meh and not thriving
• All syngo are pretty much dead (madeira, lago grande, rio negro giant)
• Ammani gracillis mini stunted (not surprised)
• Xyris is dying
• Myrio tuberculatum keeps getting lower stem necrosis

SO what's the problem??????

• Substrate: I'd put my money on the lack of adequate flow in the substrate due to compaction but others have been using the same product with great results.
• Substrate: Too deep?
• Macros: I have pretty much close to EI I think
• Micros: Too much micros? well I have not noticed any sig improvement with lower amounts (please don't start microtox debate haha)
• Light: pretty sure I have more than enough
• CO2: maybe I should whip out the pH meter again (I thought I was done with all that stuff)
• Flow: I mean c'mon!

Interested in hearing what you guys/gals think.

• 

>>>>>>>>>>>>>>>>>>>>>>CO2 video

 

[Burr740]

First let me preface this in case anyone reads it as contrary to Leibig's Law of the Minimum, which states that a plant can only have one nutrient deficiency at a time (whichever one is in least supply) What it doesnt state is that every plant in the aquarium (or forest or field) has to be deficient in the same nutrient. Some plants need more of one thing or the other

Im going to assume your co2 is as least adequate. You know enough to at least have it running consistent. But the main reason is that low/poor co2 doesnt look like a lot of these symptoms. What I see is a plethora of deficiencies going on

Most look like a macro deficiency of one kind or another (we talked elsewhere recently about your PO4) Except the macrandra. Those abnormally close internodes along with sporadic top troubles means that a micro is too low, likely Zn. But just assume you need more of them all including Fe. Go back to the suggested dose

Ammania isnt going to like this set up regardless (too much in the water, not enough in the sub) You might as well move that somewhere else, at least until this tank becomes stable

I believe youre trying to get too fancy with your dosing frequencies and all that. I know when we talked before you also mentioned you were trying to get by with a water change every two weeks for a while. But with that aside, for whatever reason your plants have gotten all out of whack, and its going to take a little time to get right. In situations like this its time to get back to the basics with something we know works

About six of my farm tanks are essentially this same set up, blasting sand sub (no your depth isnt a problem) near zero KH , and fairly high water column dosing. Im growing most of these same plants and many others too. So while I cant tell you exactly what the problem(s) is, I can tell you what I do in my tanks that works

Weekly totals of 20-25/5-7/25-30, and micros at .4-.5 Fe. Along with 50-60% weekly water changes (not 75%, not 25% - 50-60%)

Dose half the weekly total for macros right after the water change. Then divide the other 50% in two doses added as the week goes on in typical 3x week fashion. Micros can be split 3x week as usual, starting the day after the water change

Right now all your plants are starving, so Id start with the higher range of those numbers for a month or two while they catch up

You mentioned daily dosing. Daily dosing macros is not a good idea unless youre doing very small water changes, 25-30% max (some do have success with it, youre obviously not) The water change causes too big of a drop in nutrient levels that never catches up with small daily dribbles

Along with this dosing adjustment, right now you need to do a major trim and replant. Get all the crappy growth out. If the tops are bad, cut them off and leave the stumps to regrow. If the tops are good, replant those and toss the crappy bottoms. You dont want all this damaged deteriorating plant material sitting around in the tank. It wont repair itself, it'll just continue to rot, and the by product of that rot is algae food. You'll have to wait for healthy new growth to come in

Do all that and just be patient while the plants catch up

For others reading, Im not saying this is the only routine that will work for this set up, but its one that I do know 100% works

 

[OmidNiav]

You mentioned daily dosing. Daily dosing macros is not a good idea unless youre doing very small water changes, 25-30% max (some do have success with that, youre obviously not) The water change causes too big of a drop in nutrient levels that never catches up with small daily dribbles

Thanks for the reply.

1. Just to clarify micros are dosed daily (in small amounts) and macros are being dosed twice a week in this setup.

2. Regarding water changes: yes, I would love to transition to every other week. That way I can definitely keep this hobby going stronger and more manageable for myself. Maybe I can get everything healthier and then figure that out

3. Regarding micros: I used to use your recipe and mix everything and then I got the prepackaged mixes from you. I always felt like (read: no science) it was a strong mix and over time tapered things down and started doing smaller doses daily to avoid some plants getting hit with larger doses. Obviously you use your own mix and have awesome plant growth. I might have to go back to dosing micros at your recommended levels 3 times a week and see what would happen in conjunction with doing macros your way as well.

4. Please tell me you have all those 3 syngos. Mine are all dying/dead.

Worse come to worst, I lose all the plants but I think I can still source all from the community....I hope!

Thanks again,
Omid

 

[Burr740]

1. Daily dosing micros is actually fine. Unlike macros that need a certain base level in the water at all times, ideally a consistent level, with micros plants can take in small regular sips and do just fine. For daily just go to 1 ML per 10 gal instead of 2 ML

3. As long as you dont go over the suggested dose using my recipe, there's no need to worry about too much. Even a little more wont hurt, but using much less wont be enough, unless of course youre running a low nutrient routine in general

4. Oh is that vichada? I thought it was echornia just having a super rough time, lol. The only Syns I have atm are meta, macrocaulon, and madiera (thanks for that one btw!)

 

[Mr.Shenanagins]

Dose half the weekly total for macros right after the water change. Then divide the other 50% in two doses added as the week goes on in typical 3x week fashion.

Curious why you don’t just front load all? Whats the benefit or reason for splitting it up like you do? Just curious

 

[OmidNiav]

1. Daily dosing micros is actually fine. Unlike macros that need a certain base level in the water at all times, ideally a consistent level, with micros plants can take in small regular sips and do just fine. For daily just go to 1 ML per 10 gal instead of 2 ML

3. As long as you dont go over the suggested dose using my recipe, there's no need to worry about too much. Even a little more wont hurt, but using much less wont be enough, unless of course youre running a low nutrient routine in general

4. Oh is that vichada? I thought it was echornia just having a super rough time, lol. The only Syns I have atm are meta, macrocaulon, and madiera (thanks for that one btw!)

Yes the eicchornia is kinda miserable but I think coming back. I don't have the vichada. I will grab some syngos from you as soon as this tank stabilizes.

 

[Burr740]

Curious why you don’t just front load all? Whats the benefit or reason for splitting it up like you do? Just curious

I spent a couple years front loading it all. Thats actually better than 3 equal doses through the week. It wasnt exactly bad, but it doesnt make as consistent of a level from day 1 to day 7. Its heavy at the start, and low at the end

Doing it this way maintains a steady baseline by adding the larger amount right after the wc, and the two doses through the week more or less takes care of plant uptake.

Thats my theory anyway. For whatever reason doing it like this grows plants better overall than any macro routine Ive ever tried

 

[OmidNiav]

Curious why you don’t just front load all? Whats the benefit or reason for splitting it up like you do? Just curious

You definitely can. This is just another way. By splitting, at least in my opinion, your system wouldn't get hit by very large amounts of nutrients and some sensitive species do better.

 

[Burr740]

And before anyone asks (or wonders to themself) "Well if plants only use 2-3 ppm NO3 per day, why the need for the excess "baseline" in the water to begin with? Why not just add what the plants actually use?"

First thats a very good question. It does sound logical right? The two main reasons are

Because the presence of other nutrients has an affect on plants being able to absorb and use other ones as well. In most tanks Ca is the highest nutrient present. Some tanks run well with 15 ppm or so, very few have less. Most tanks its in the 30s or higher. So there needs to be a certain level of NO3, K and PO4 in the water too because those all have an antaginistic relationship with each other. See Mulders Chart of Nutrient interactions. There is also the issue of ionic balance that plants strive to maintain (slight lean to the neg)

The other reason is the difference between active absorption and passive absorption. A lot of nutrient uptake is passive, meaning the plants take in nutrients at a rate determined by how much is present in the water (think of it like pressure inside vs outside, different mechanism but it paints the picture) Plants cant always reach out and grab a single ppm just because thats all they actually need, or hit the off switch when they have enough

Those are two main reasons why, there may be others

Note that this "baseline" becomes higher when using and inert substrate, where its more critical to have enough of everything in the water. Rich subs can sometimes function really well dosing very little in the water, if done right. Dennis' method is a good example of this. My comments in this thread all relate to inert or weaker substrates

 

[Kwyet]

I’ve never understood that. Thanks for the explanation!

 

[SkaleyAquatics]

Out of curiosity do you know your par? I wonder if you are not dosing enough macros for the amount light you are blasting on the tank. Also it looks like you bought the medium grit BDBS but want to confirm? I do not notice much compactness with it but I also vacuum it out every few weeks.

But I agree with Joe to cut all the crappy growth and up macro numbers.
Just FYI all my BDBS tanks get 30-10-40 for macros. Split into 4 doses essentially a double dose at water change time and then the remaining split into 2 doses. I also do 50-60% changes. I was doing closer to 75% when they were initially setup.

If your goal is to reduce maintenance you will probably want to lower light intensity and ferts some once you get this tank stabilize. I run all my WA and Chihiros at 50% light intensity and dose the numbers above and can get away with every other week water changes if need be but it is not my norm.

 

[OmidNiav]

Out of curiosity do you know your par? I wonder if you are not dosing enough macros for the amount light you are blasting on the tank. Also it looks like you bought the medium grit BDBS but want to confirm? I do not notice much compactness with it but I also vacuum it out every few weeks.

But I agree with Joe to cut all the crappy growth and up macro numbers.
Just FYI all my BDBS tanks get 30-10-40 for macros. Split into 4 doses essentially a double dose at water change time and then the remaining split into 2 doses. I also do 50-60% changes. I was doing closer to 75% when they were initially setup.

If your goal is to reduce maintenance you will probably want to lower light intensity and ferts some once you get this tank stabilize. I run all my WA and Chihiros at 50% light intensity and dose the numbers above and can get away with every other week water changes if need be but it is not my norm.

No idea on PAR but I see your point. As for the bdbs, it is the medium.

Will give it more time and go with all recs and see what happens.

 

[Pepere]

And before anyone asks (or wonders to themself) "Well if plants only use 2-3 ppm NO3 per day, why the need for the excess "baseline" in the water to begin with? Why not just add what the plants actually use?"

Thank you so much for thinking to address this unasked question…

Addressing it was incredibly helpful.

 

[Pepere]

Because the presence of other nutrients has an affect on plants being able to absorb and use other ones as well. In most tanks Ca is the highest nutrient present. Some tanks run well with 15 ppm or so, very few have less. Most tanks its in the 30s or higher. So there needs to be a certain level of NO3, K and PO4 in the water too because those all have an antaginistic relationship with each other.

So, following this logically, would it be safe to assume if we had sensitive enough nitrate testing equipment, if the base level of macros were too low for the amount of Ca and Mg in the WC we would see the levels rise over time as plant uptake was diminished until it reached a higher base level and plant uptake increased?

 

[Burr740]

So, following this logically, would it be safe to assume if we had sensitive enough nitrate testing equipment, if the base level of macros were too low for the amount of Ca and Mg in the WC we would see the levels rise over time as plant uptake was diminished until it reached a higher base level and plant uptake increased?

Eh...I get the logic. But wouldnt this would imply that both growth and no3 uptake would stop completely at the theoretical "point of deficiency." I believe no3 levels would continue to drop as the plant(s) continued to grow albeit in a deficient state. In other words NO3 would keep dropping and the plants would just get progressively worse. Nothing would freeze or stand still for this catch-back-up period

Another problem with the hypothesis is other plants in the tank would continue to grow and thus further use the existing no3, deficient or not. Unless it was a tank full of a single species. In that case, well refer to paragraph one

What a mind bending question! lol. Obviously Im just speculating and thinking out loud on the reasons, but I think the short answer is no

 

[Pepere]

What a mind bending question! lol. Obviously Im just speculating and thinking out loud on the reasons, but I think the short answer is no

Thank you for your thoughts. Exploring this further, do you think this is the cause for poor growth in hard water?

Also, most fresh water bodies, absent agricultural runoff, soils erosion, lawn fertilization run off, or failing septic systems, have nitrate levels below 5 ppm And some of them are hard water bodies. Yet aquatic plants grow in them. Sometimes quite profusely.

Any thoughts on that scenario?

 

[OmidNiav]

Thank you for your thoughts. Exploring this further, do you think this is the cause for poor growth in hard water?

Also, most fresh water bodies, absent agricultural runoff, soils erosion, lawn fertilization run off, or failing septic systems, have nitrate levels below 5 ppm And some of them are hard water bodies. Yet aquatic plants grow in them. Sometimes quite profusely.

Any thoughts on that scenario?

Wouldn't that depend on the type of plants? I'm assuming by hard water you mean presence of high CO3/HCO3 levels that some plants can use as a carbon source when co2 is scarce. In such environment there could be a large source of "ferts" in the substrate due to lower leaves/stems dying and settling on the bottom creating a source of NPK. I'm just speculating here obviously.

 

[Burr740]

Yeah there are so many variables in that scenario its hard to say. But also just because plants are growing in certain natural conditions doesnt mean they are growing in a way that would be considered nice in our tanks. Or that we can duplicate those natural parameters and have similar results

There's too much difference between what happens in a stream or river and what happens when we put a few gallons of water in a box. The only way to know would be copy the parameters using the same plants and see what happens

 

[OmidNiav]

Yeah there are so many variables in that scenario its hard to say. But also just because plants are growing in certain natural conditions doesnt mean they are growing in a way that would be considered nice in our tanks. Or that we can duplicate those natural parameters and have similar results

There's too much difference between what happens in a stream or river and what happens when we put a few gallons of water in a box. The only way to know would be copy the parameters using the same plants and see what happens

I never considered what happens in our tanks as "natural." As many cool natural environments with happy plants that I have seen pictures/videos of, I've seen more of ugly plants in muddy water rivers/lakes! We are not imitating nature we are playing god on a small scale.

 

[Koan]

we are playing god on a small scale

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