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Aquarium sand and diatoms...

Hi Gareth (@Wookii)

Good to be 'talking' with you.

When you do your 50% water changes, do you also clean out the canister filter?

JPC

Just the pre-filter, which takes a about 5 minutes, the main filter then about every 2-3 months.

Hi Gareth (@Wookii)

Perhaps we should discuss this by PM/Conversation. It's my fault going off at a tangent.

John

Yeah, feel free to drop me a PM at any point John.
 
Here is what I mean:
Diatoms cannot handle as much light as plants since they are brown. They absorb more wavelengths. So, we can laser them before killing our plants. People can run high PAR algae free without killing everything - so what is excessive light? Just balance the light below the point of incinerating the plants, and then you can incinerate the diatoms.

The same may be said for BBA. But, is it the plants becoming healthy that eliminates them or the light? No clue - but I still don’t know what excessive light means.
The answer is no. All of these statements are wrong. In fact it's just the opposite and brown has nothing to do with anything.
With CO2, you can get an idea of CO2 concentration from the humble drop checker. But, how do you categorically know that you have "poor nutrient levels" if you don't measure these with test kits or other instruments?
Well, you'll have to spend a lot of money to find an instrument that can accurately and consistently measure nutrient levels. You'll not know from a hobby test kit reading
Growth was stunted and there was some yellowing of the leaves. To my untrained eye, I suspected nitrogen, iron, magnesium or manganese deficiency. I tested the first three of these nutrients but all was OK. So, I then decided to test for inorganic phosphate and it was <0.02 mg/l. I added a phosphorus compound to the water and the plant perked up.
Yeah, something else was going on or you did something (or didn't do something) that is unaccounted for. PO4 cannot fix yellowing. That isn't it's function. That's the function of Nitrogen and some micronutrients such as Iron.
To which chemical(s) are you referring? The (Boyd) article that I referenced previously would suggest silicic acid.
Chemicals such as NH3/NH4, organics and so forth.
No, as I mentioned it doesn't suggest anything of the sort because it addressed higher plants, not algae, and it was a very specific scenario, not one that we encounter in our tanks.
You “can’t” learn to diagnose nutrient deficiencies without ample experience and/or being able to rule out all of those things EI teaches you.
I don't know what the big deal is. I mean, everything we do has to be learned. Why is this so difficult? We have provided all of the the information necessary. 95% of our problems is CO2 related. After that one only needs to think about the the macronutrients. Even so, if one has difficulty, then just add more of everything. That way one need not think.

But no, everyone want to buy a test kit and play pharmacist. Then the kit tells lies and off we go to see the wizard of Oz.
That's why you have difficulty. How hard is it to keep what Darrel just said in mind? If new leaves have discoloration it's a micronutrient problem, if it's old leaves then its a macronutrient problem. If it's micronutrient issue why on Earth would you just add one micronutrient? Add all of them because they are all suspect. This policy is so easy that trying to isolate a single micronutrient becomes absurd. How many times do we need to say that if you are adding nutrients, especially EI level of nutrients and are still showing deficiency then that means you have a flow/distribution issue and you need to fix that, not add more of anything.

Cheers,.
 
Well, you'll have to spend a lot of money to find an instrument that can accurately and consistently measure nutrient levels. You'll not know from a hobby test kit reading

95% of our problems is CO2 related.

Hi @ceg4048

Do you have scientific evidence in support of the generalized statements above? The terms "accurately" and "consistently" need to be qualified. I am satisfied that many, but not all, hobby test kits are sufficiently accurate and reliable to justify their use. Otherwise, for me, it's all just guesswork. I don't have the experience to just look at an ailing plant and say it's deficient in X or Y. Dismissing all hobby test kits out of hand is something I can't get my head around. I am also OK with agreeing to disagree on these topics that seemingly divide people. Let's leave it at that - please.

JPC
 
Hi @ceg4048

Do you have scientific evidence in support of the generalized statements above? The terms "accurately" and "consistently" need to be qualified. I am satisfied that many, but not all, hobby test kits are sufficiently accurate and reliable to justify their use. Otherwise, for me, it's all just guesswork. I don't have the experience to just look at an ailing plant and say it's deficient in X or Y. Dismissing all hobby test kits out of hand is something I can't get my head around. I am also OK with agreeing to disagree on these topics that seemingly divide people. Let's leave it at that - please.

JPC
Hi JPC,
Why is it always the victims of disinformation who are obliged to provide scientific evidence? I mean, why aren't the test kit makers and test kit lovers ever asked for scientific evidence? You may be aware that Einstein, when asked whether his theory of relativity could be proven, responded; "No number of experiments that agree with the theory can ever prove the theory as fact, but it only takes one experiment to disprove it." That's why 100 years later it is still referred to as The Theory of Relativity.

So taking this tack is how we collectively arrived at our conclusions. Using samples of RO water with known solute concentration levels and using the kits to compare with those known values the kits often fail. Even if they are close or bang on a few times, statistically they exhibit random successes. So this is how they behave with your tank water, randomly successful. It is suggested to plot the error of various concentrations and then to use the plot to make adjustment to the readings.

A similar tack is used to disprove the notion that "nutrients causes algae". This is a popular non sequitur. If someone claims PO4 causes algae and if I add PO4 yet don't get algae - and if I can do this repeatedly with similar results they I can be satisfied that the notion is wrong. If someone needs to see an example of this please check the EI Methods thread in the Tutorial section of the forum. That tank was dosed with between 3X to 5X EI dosing because I wanted there to be no doubt in my mind that nutrients do not cause algae.

It's a similar story chasing the root cause of diatomic algae. I'll not likely "prove" the cause(s) the blooms, but it's easy to disprove the notion. I mean, good Lord, have you (or any silicate test kit lover) actually added a silicate source to a perfectly stable tank and observed a sudden increase in diatoms? Does your water report state a silicate level? Why does a bloom not appear every water change when a fresh new supply of silicate laden water is added? Why do folks who experience diatoms at tank startup suffer for a few weeks and then observe the diatoms disappear?

These are questions people reading this thread need to think about. . Most important to me is that inexperienced hobbyist or others who suffer difficulties at least try to think critically instead of running to the LFS for some test kit when they experience a problem just because of populist propaganda. We've already laid out the basic principles of plant deficiency analysis, which greatly simplifies the troubleshooting and the resolution techniques.

Cheers,
 
id scraped all diatom growth from the glass and gave the plants a bit of a cleanup when I posted this. n 7 days later, and its starting to form on the glass again. (although not a lot of it at present)
I still need to make spraybar v3 (smaller holes) to give a bit more oomph to the water movement, however the rear to front flow does seem better
 
Hi @dcurzon - I always get diatoms in a setup - I let it grow and just roughly take some out using a tooth brush - only the major bits, I leave the minor bits. Then...when the tank is cycled I add ottos and amano shrimp - all diatoms gone within 2/3 days. Diatoms are a type of eukaryotic cell that can metabolise silicon/silica. Therefore, it can thrive in a tank containing high concentrations of silica. I have experienced more diatoms when using quartz gravel vs ADA la planta/colorado sand. Hugo Kimishi gravel and sands are decent too. Once we resume to normality, I will get some project students in my lab so run analysis on different brands of sands/substrates to determine their exact composition and report back. Don't hold me to this as I will have to find the time and a pair of hands to do this....far too much teaching to do at work but I will try. I have had diatoms in tanks which I have reported on my YouTube channel (Natquascape). Hope that helps.
 
Hi all,
I will get some project students in my lab so run analysis on different brands of sands/substrates to determine their exact composition and report back
I'm very interested in this one. Are we talking about the molybdenum blue method?

I'll nail my colours to the mast, and say I'd be really surprised if they weren't all 100% SiO2 and pretty much <"insoluble at normal temperatures and pressures">.
... Diatoms are a type of eukaryotic cell that can metabolise silicon/silica. Therefore, it can thrive in a tank containing high concentrations of silica.
But only if it is in the form of an orthosilicic acid (H4SiO4)?

I've been told that freshwater always contains enough "diatom available silicon" for diatom growth, mainly because they are incredibly efficient at extracting it. My understanding is that once the silica is incorporated into the diatom frustule it is unavailable to any other diatoms, because of its insoluble nature.

cheers Darrel
 
Hi Folks,

I thought it might be a breath of fresh air to admire the sheer fractal beauty of diatoms. To that end, please feast your eyes on the attached piccie. There are lots of photomicrographs of diatoms on the internet. Breathtaking, eh?

JPC
 

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Hi all,
admire the sheer fractal beauty of diatoms
There is some brilliant <"Victorian slides etc">.
Would that be the same method used by JBL?
I don't know, if it includes citric acid (to remove PO4---)? it probably is.

I've never actually tested for silicon /silicate, by any means. You have other things to worry about in waste water work and it has never been of interest to any-one I've worked with.

We have had an <"interest in diatoms"> (both in sediment cores and planktonic and benthic diatoms from lakes and streams etc.) because of their use in the <"trophic diatom index">, they are useful for this <"because all freshwater contains diatoms">, including <"really oligotrophic lakes etc">, where other organisms may be in very short supply.

Because the frustules are insoluble they remain intact (which is why you can retrieve them from sediment cores and reconstruct <"the water conditions when they were living">), but they need careful handling (they are basically tiny cups of etched glass)), which means cleaning up with strong acids etc.

cheers Darrel
 
Once we resume to normality, I will get some project students in my lab so run analysis on different brands of sands/substrates to determine their exact composition and report back.
Could you also ask them to test/measure the solubility of the silicon compounds?
 
some additional plants added, and, local P@H had one lonely little Otto in their tank, so I brought him home and plopped him in. Kept a careful watch because, well, Tiger Barbs... but a day gone by and I still have an Otto. They should have more later in the week so I'll keep an eye on this one and if all goes well I'll get him some buddies.
 
some additional plants added, and, local P@H had one lonely little Otto in their tank, so I brought him home and plopped him in. Kept a careful watch because, well, Tiger Barbs... but a day gone by and I still have an Otto. They should have more later in the week so I'll keep an eye on this one and if all goes well I'll get him some buddies.

Hi dcurzon,
I might have missed it, but I thought in one of your earlier post you stated that you actually turned the CO2 down? Have you turned it back up? Also, I'm not seeing a DC in the photo. Have you performed a pH profile to help understand how the CO2 is behaving? We need to know whether the CO2 is sufficient when you turn the lights on. We should have asked for that earlier.

If you float a tiny bit of paper on the surface you should be able to track it's path to give you an idea of how the flow/distribution is.
It also looks like you changed the light, which means you've added another unknown to this equation.

Could you also restate your dosing regimen?

Cheers,
 
Hi dcurzon,
I might have missed it, but I thought in one of your earlier post you stated that you actually turned the CO2 down? Have you turned it back up? Also, I'm not seeing a DC in the photo. Have you performed a pH profile to help understand how the CO2 is behaving? We need to know whether the CO2 is sufficient when you turn the lights on. We should have asked for that earlier.

If you float a tiny bit of paper on the surface you should be able to track it's path to give you an idea of how the flow/distribution is.
It also looks like you changed the light, which means you've added another unknown to this equation.

Could you also restate your dosing regimen?

Cheers,
Hi @ceg4048
I had to send my pH checker back to Amazon (waiting on credit refund) as the readings were screwy and it wouldn't let me calibrate... So I've moved the DC from tank #2 to this one, and will be adjusting over the course of the next few days.
I shall order a replacement pH checker and re-profile.

Watching the food when dropping it in, I can see it travel across the top, down the front then a wisp back towards the rear. By this point the barbs have either got it, or their frenzy is affecting its path anyway. The stems at the back have a slight movement in the water. Not swaying, more like leaves gently shimmering.

Dosing
I use the same EI mixes across tanks, just adjusting the volume added according to tank size. Alternate daily macro/micro, although I might miss a day now and then.
Per week, im adding roughly:
NO3: 12.7ppm
PO4: 2ppm
K: 20ppm
Mg: 7.5ppm
Ca: (tap is 36ppm)
Fe: 0.36ppm

You're absolutely right, ive made multiple changes in an attempt to improve things, which to be honest I should know better.
 
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Watching the food when dropping it in, I can see it travel across the top, down the front then a wisp back towards the rear. By this point the barbs have either got it, or their frenzy is affecting its path anyway. The stems at the back have a slight movement in the water. Not swaying, more like leaves gently shimmering.
Okay, yes, this is what we want to see. If you have the reagent style pH test kit you can take the measurements while you wait. I'm an advocate of purchasing high quality pH probes, such as the Hanna brand and other top brands. As much as people winge about pH you'd think they would invest in a quality probe and calibration solutions.

In any case, it may take a few weeks of obsessive cleaning and water changes before this issue is resolved, but make best efforts to ensure a high CO2 level at lights on.

Cheers,
 
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