Effect of massive amounts of phosphate?

[Carissa]

I have this recurring problem that I can't explain. Several months back I had the same problem. It manifests on my hygro leaves as pieces of the leaves (new growth) actually missing, almost like something is eating it, but nothing is. I started co2 injection and it appeared to stop when I started doing co2 the first time, so I figured it must be a manifestation of carbon deficiency (although this was a different reaction from what the same plant did before when I stopped co2 injection).

Anyway, I stopped co2 injection again, but this time I actually removed and threw out all my hygrophila since I knew I would have problems with it. I took some hygro from another totally non-co2 tank where it had been for months or years, and planted it in the tank. Everything went well for two - three weeks, nice, slow steady growth. Then, the same thing started happening again with pieces missing from the leaves. I know it sounds like a deficiency, but if it's not carbon, how can it be something else - since with less co2, less uptake, should = more of all nutrients available. I should see it manifesting when I START co2, not stop, if it's a nutrient deficiency, right? Last time it happened, I increased EVERYTHING and it didn't fix the problem, but starting co2 injection did, eventually.

Anyway, coincidentally, I got a phosphate test kit when this started happening again and tested the water for kicks. I got a massively high level of phosphate (well over 10ppm, off the chart). Could it be that the excessive phosphate is somehow causing this, and injecting the co2 was just creating more demand, thus reducing it to normal levels and producing normal growth, until it built up again after eliminating co2?? I can't come up with any other hypothesis that fits all the facts. My next step, I guess, is to do some major water changes to remove the phosphate, and see if it goes away or what the deal is.

 

[SpeedEuphoria]

well 1st step would be calibrating your phosphate test kit if you havent already. I have an API kit that I have yet to calibrate but it always gives me high readings

 

[Carissa]

Well.... I'm fairly certain it must be ridiculously high. It turns almost black immediately after adding the drops, and the directions say to wait 5 minutes for color development. I tried it on some water that I know is at or near 0 phosphate and it did come out accurately. If it was reading 4 or 6 ppm that could be iffy, but not if it's reading off the scale instantly and not doing that in low/0 phosphate water, I can't see the kit being at fault.

 

[ccLansman]

ide like to hear a good solution, as i find the same results with my API test kit, always goes to dark blue or black as soon as i add the second drops.

how do we calibrate our test kit?

edit: BTW great looking site Carissa!

 

[Carissa]

Thanks!

I just did some testing with my test kit. First I tested RO water, then tap water, then tap water to which I had added an additional 1.68ppm of phosphate (well, probably with a 15% degree of error).

My results were:
RO = 0ppm
tap = 0.5 ppm
tap to which I added ~1.6ppm: 2.0 ppm

So although the resolution isn't the greatest, I think I can safely trust that if it's giving me a 10+ ppm reading, it's probably right.

 

[ccLansman]

how did you go about adding 1.6ppm?

 

[Carissa]

Used this site:

Calculating dosages of fertilizer elements for a planted tank

I added .25 tsp (the smallest amount that I figured I could measure with any degree of accuracy) to 500 ml, then added 2 ml of that to 2 L of water. I used a ml syringe to measure the liquid. So any inaccuracy that would have resulted would have been because I used a 1/4 tsp measure for the powder. But I figure I probably got within 10% one way or the other, probably less than that, so I should be between around 1.5 - 1.75ppm. Close enough. The resolution of the kit doesn't go down that far anyway.

 

[Carissa]

No ideas about the strangely growing leaves? I started using Excel and it's had no apparent effect yet (in about a week). This is frustrating.

 

[Tom Barr]

Massive might be over say, 5ppm of PO4.............
The point where it starts to effect planted tanks is when it starts acting like a buffer.
There's no toxic effects I know of or am aware of other than salt stress, which means 100ppms and more on any plant, algae or critter.

See Estimative Index subforum on how to make a simple set of PO4 and NO3 standard solutions to calibrate the test kit.

LeftC posted it.


Regards,
Tom Barr

 

[Carissa]

It's definitely over 10ppm, well over. If it's acting as a buffer, would it drive the pH up, or what would be the effect?

 

[DaveSurfer]

Critters?

It's definitely over 10ppm, well over. If it's acting as a buffer, would it drive the pH up, or what would be the effect?

Hey Carissa, do you have any loaches in your aquarium. Namely, clown? I had tonnes of Hygro that grew wild in my aquarium and I noticed little bites out of the leaves...and only the new growth as I suspected the newer growth is much more tender.

I never actually saw them nibbling at the leaves but they probably do so at night as they feed nocturnally as well.

Anyways, when I got rid of the clowns I never had any more bite marks on the Hygros. I didn't think it was a big deal as my Hygros grew faster than they could takes bits off of them. I also noticed that when I started feeding more shrimp pellets and introduced snails (accidently with some plants) the biting nearly stopped.

Anyways, I might be wrong be think about it.

 

[Carissa]

Nope, no loaches. I did see one of my angels taking a bite yesterday. I see this occasionally, But the thing is that I've had the angels for like 8 months, so why would they do it erratically? So I'm pretty sure it's nutrient related. My anubias leaves are looking wavy now, not sure if that's a weird side effect of Excel or nutrient related. Since I know nitrates and phosphate is plenty high, I added more potassium and traces yesterday, although I can't imagine either one of those being low based on what I had been adding. I also added calcium the other day, although GH is around 4 or so. Only thing left to add is magnesium. Would pH cause an issue? The pH is about 8.2. This is because the water I use for changes has a high KH.

 

[DaveSurfer]

Nope, no loaches. I did see one of my angels taking a bite yesterday. I see this occasionally, But the thing is that I've had the angels for like 8 months, so why would they do it erratically? So I'm pretty sure it's nutrient related. My anubias leaves are looking wavy now, not sure if that's a weird side effect of Excel or nutrient related. Since I know nitrates and phosphate is plenty high, I added more potassium and traces yesterday, although I can't imagine either one of those being low based on what I had been adding. I also added calcium the other day, although GH is around 4 or so. Only thing left to add is magnesium. Would pH cause an issue? The pH is about 8.2. This is because the water I use for changes has a high KH.

Yeah I've never had any issues with Angels but then again I had harder-leafed plants like Amazons in those aquariums.

Can you post a picture of this? I doubt it's a nutrient problem. I've seen hygro grow successfully in nearly every type of tank, though it does grow crazily with CO2 and high-light...much too fast in my opinion.

Is this just the normal green hygro or is it a different type? I'd look at your other simular green colored plants and look for any issues. please post a pic though!

 

[Carissa]

It's regular hygro. Here's a pic from the last time it was happening, it went away for a few months and then started happening again. It looks the same. There is also algae growing on the edges of the leaves (including older growth that looks otherwise normal), which is partly why I'm thinking it must be nutrients. You'll see a bit of gsa in the pic, that's mostly gone now but the edges of some leaves still have algae. What throws me is that it's not happening consistently since I added the angels. It was fine at first, then a couple months later it started, then fine, then a couple months after that it started again. For the amount of damage I'm seeing (every single new leaf), I would think that I would be seeing my angels eating the plants all day, there are only two of them. But it's only occasionally I see one of them attacking a plant. All the fish are pretty well fed too. The only other plants I have are some ludwigia, java ferns, and anubias and crypts; but being all slow growing plants, I would expect to see a deficiency in the hygro first or perhaps exclusively. When I had the issue with carbon deficiency, the hygro was the only plant to show any symptoms, apparently because it is a much faster growing plant with higher demands for nutrients. That's what I thought this was, since it is coinciding both times with my stopping co2 injection. But this time when I stopped co2, I moved these plants from a non-co2 tank into this tank and threw away all my hygro that was growing with co2 in order to avoid this problem. But yet I see it again in plants that can't be co2 deficient. So then I come down to, what's different in this tank other than co2 levels, that changes every time I stop co2? Higher nutrients probably, and slower growth in general. So is it the high nutrients causing this, or maybe it's just growing slow enough now that it can't outpace the angelfish?

 

[Naja002]

It's definitely over 10ppm, well over. If it's acting as a buffer, would it drive the pH up, or what would be the effect?

Any insight to that question?

 

[Tom Barr]

It will act as a weak acid, so it will reduce pH, not increase it. You will think you have more CO2 than normal.

PO4 has little other physiological effect on plants, or critters.
10-20-50ppm etc, there's no toxicity data at high levels. Well, it acts like NaCl once you start talking about Salinity and reaching parts per thousand........quite hard to do that with a typical dosing error

Regards,
Tom Barr