# Old Skool Returnee - London tap water?



## tony456 (29 Oct 2012)

Hello I'm new here and looking for some advice.

I live in central London and kept a reasonably successful planted tank for about six years. I eventually dumped it a few years back in favour of keeping cichlids, mainly because I wasn't comfortable with the amount of waste water my RO unit was pouring down the drain.

I used very soft RO water, CO2 injection, a single 150w metal halide, low turn over filtration, no ferts except iron but plenty of fish and food. After some teething problems it ran pretty sweetly for a good few years.

Back then orthodox thinking said you had to go the soft water route and I'd taken that as gospel until I came on here. Wow, you hypermodernists have torn up the rule book! So now I'm seriously toying with getting back into the game. I've still got my CO2 gear (huge pub cylinder, regulators, solenoids, timers), I've got filters and pumps for as much movement as is needed and I'd want to go LED instead of MH. I'm reading and learning on the whole EI, light, CO2 relationship.

The sort of tank I'd like to try would be based on mosses and liverworts growing on wood suspended in the water column. I'd not intend to use any substrate on the bottom. I'd want to keep plenty of fish. Possibly a large group of a single species. The tank (to be custom built) would be large and a little unusual in proportions - 180x70x30cm with 70 being the height.

So the questions.

1. That rock hard London water, do I really not need to worry about all that KH? Are mosses and liverworts going to do well?
2. I sense 'ceg' is going to growl at me now but here goes. How much light should I be looking for? Watts/gallon don't mean much when it comes to LED so can anyone give a figure in terms of PAR or better still lumens as a least I know what they are.
3. Would mosses and liverworts be suitable from the get go or do i need to start with some valis or similar to get the tank mature and gradually replace them?
4. What fish will thrive in London water? Is there a hard water equivalent of the amazonian tetras? I'd like a large group of very small fish to bring movement and focus in the water column. Ottos and shrimps are not enough!

Looking forward to hearing some advice the cutting edge!

Thanks - Tony


----------



## tim (29 Oct 2012)

Hey mate I can only comment on the tap water I haven't had any issues with cardinal tetras black neon tetras or glass blood fins kept in London tap tanks well planted dwarf shrimp on the other hand I'm cutting tap half and half with ro for my cherry shrimp nano and don't lose as many as when I first started keeping dwarf shrimp a couple of years ago hope this helps


----------



## tony456 (29 Oct 2012)

Thanks Tim, my experience with cardinals was a bit like yours with shrimps. They did okish in London tap but it was a different story when I switched to a soft water set up. They lived longer, grew much bigger, showed a lot more vitality and there was some breeding, although few survived predation. Ideally I'd be looking for something with those sort of shoaling characteristics but with more of an affinity to hard water.


----------



## ceg4048 (29 Oct 2012)

Here's what I don't get; how come people who can afford a custom built 180 Megaton Galactic Starship Cruiser of a tank can't afford a PAR meter? Also, how come the first question is always how much light do I need, instead of how much CO2/flow and distribution do I need?    

As it turns out, mosses and liverworts do not really need a lot of light. They can practically grow in the dark. What they care about is CO2 and flow, and, if the lighting is too high they turn to brown mush - unless the CO2 is kept high. Also, these plants do not really care about RO water. Some plants do care, plants like R. macandra, Tonina sp and some of the more exotic  forms of Ludwigia, but these are only a handful.

Vallis will do well in high KH water. Some plants, perhaps 50% of available species will externally manipulate the CO3/HCO3 that causes KH in water, will convert it to CO2 and will then uptake the resulting CO2.

In any case, whatever LED lighting units you get, make sure that it comes with a dimming controller. That way you can get as many as will fit over the tank. The TMC GroBeam 1000 ND LED tiles are popular and to cover your distances might require 4 or 5 of these tiles. The 
Radion XR30w is another expensive option and you could probably get by with three of these as they are double cluster units. Of course you're not limited to these two brands, there are many others, but we just know about these more than others. There is also the DIY option as well which is much cheaper.

Cheers,


----------



## OllieNZ (29 Oct 2012)

I've personally had no problems with cardinal tetras or harlequin rasboras (thames valley water oxford).

A few others to consider




http://www.seriouslyfish.com/species/pseudomugil-gertrudae/




http://www.seriouslyfish.com/species/iriatherina-werneri/




http://www.seriouslyfish.com/species/melanotaenia-praecox/

All small, schoaling and naturally from hard waters. In a tank that big Id be tempted to try one of the larger rainbowfish spiececs


----------



## tony456 (29 Oct 2012)

> Here's what I don't get; how come people who can afford a custom built 180 Megaton Galactic Starship Cruiser of a tank can't afford a PAR meter? Also, how come the first question is always how much light do I need, instead of how much CO2/flow and distribution do I need?


Thanks ceg. In fact how much much light do I need was my second question, but I'd have felt a little disappointed if I'd failed to draw a spikey response from you!

Yes its a big tank but budget is not limitless, sadly. I have credit at my LFS who are also tank makers, since I sold them my breeding colony of tropheus. That should largely cover the tank build. They're supplying the tank only. Stand, plumbing lighting and the rest are down to me. I didn't say I wouldn't buy a PAR meter because I didn't know there was such a thing. Any suggestions which one?. I'm a cameraman and I have some understanding of light and some ability to measure it, but in lumens not PAR. Most lights that I've come across measure their output that way so its easier to get a relative sense of the output, for me anyway. I've got kit to provide CO2 and some thoughts on achieving good distribution. Like I said I'm from the old school where more is more when it comes to light. But hey give me a break, I'm doing my best to get with you modernists. I've read some of your posts on light levels and CO2 demand and supply and the dangers of over lighting. Look I don't want to use more light than I need and if I can get good results from a few glow worms thats fine by me but, isn't too low a lighting level likely to result in thin stringy growth? Perhaps its another old school hangover but I had the idea that more light meant denser, more compact growth - given sufficient CO2 of course, before you grump at me some more!



> Vallis will do well in high KH water. Some plants, perhaps 50% of available species will externally manipulate the CO3/HCO3 that causes KH in water, will convert it to CO2 and will then uptake the resulting CO2.



Yes but I was under the impression that CO2 assimilation this way was draining on the plants' energy reserves and not sustainable long term. More old school?

As for LEDs budget does become important and wall to wall dimmable units would be too much given the tank length. I was thinking in terms of two or three units with plants concentrated in the light footprint and less well lit areas of open water between. I was thinking about the arcadia eco aqua spotlight. Its not dimmable but i could adjust the height of the unit and/or use neutral density lighting gels to knock back the output if required. DIY is a possible option too.

Thanks again for your help. All best Tony


----------



## tony456 (29 Oct 2012)

Thanks Ollie, some interesting options to explore there.


----------



## ceg4048 (30 Oct 2012)

tony456 said:
			
		

> ..Yes its a big tank but budget is not limitless, sadly. I have credit at my LFS who are also tank makers, since I sold them my breeding colony of tropheus. That should largely cover the tank build. They're supplying the tank only. Stand, plumbing lighting and the rest are down to me. I didn't say I wouldn't buy a PAR meter because I didn't know there was such a thing. Any suggestions which one?


Oh, Ok, I'm with you. I thought you might have been Captain Kirk with Federation of Planets type budget. Oh well, that's life. PAR meters are a little expensive in Europe so if you know someone heading to USA have them pick one of these up for you, or search for one used on flea-bay.==> Apogee Quantum Meter



			
				tony456 said:
			
		

> Like I said I'm from the old school where more is more when it comes to light. But hey give me a break, I'm doing my best to get with you modernists. I've read some of your posts on light levels and CO2 demand and supply and the dangers of over lighting. Look I don't want to use more light than I need and if I can get good results from a few glow worms thats fine by me but, isn't too low a lighting level likely to result in thin stringy growth? Perhaps its another old school hangover but I had the idea that more light meant denser, more compact growth - given sufficient CO2 of course, before you grump at me some more!


Allright, Allright, all cameramen get a free pass. We've gotta keep them sweet so that they donate cool pics and/or video (and/or equipment) to the website. But wait a minute....who says low light causes stringy growth? I went to Old School and learned a lot. This, well this is more like "Old-Hanging-Out-by-the Street-Corner-Playing-Hooky-From-School." Elongation has to do with poor gas exchange when a plant is submerged. Have a read of the following threads:
viewtopic.php?f=3&t=22840
viewtopic.php?f=3&t=16038



			
				tony456 said:
			
		

> ceg4048 said:
> 
> 
> 
> ...


Errr...no, more hanging out mate. CO2 is king, everything else is secondary. Nothing else is possible without the sugar created by fixing Carbon, so plants will go to great lengths to obtain this fuel wherever it can be found.



			
				tony456 said:
			
		

> As for LEDs budget does become important and wall to wall dimmable units would be too much given the tank length. I was thinking in terms of two or three units with plants concentrated in the light footprint and less well lit areas of open water between. I was thinking about the arcadia eco aqua spotlight. Its not dimmable but i could adjust the height of the unit and/or use neutral density lighting gels to knock back the output if required. DIY is a possible option too.


Well, spotlights are an option. I don't prefer them but that's just an opinion. You should definitely look into DIY. There are a couple of DIY LED threads in the lighting section, well worth a read.

Cheers,


----------



## tony456 (31 Oct 2012)

Thanks again Clive. Hope you don't mind if I run a few more thoughts past you.

Early warning - I'm going to ask you how much light do I need? But not just yet...

Yes PAR meters are expensive. Turns out a lot of the LED units give a PAR rating on the spec and it should be possible to make a reasonable guess on the others so I'm going to muddle by without one.

Stringy plants. Here's what I think you're telling me with the links. Old school says - most aquarium plants are amphibious, they're biologically programmed to seek light just like a terrestrial plant, solution - more light. School of the avant guard says - they are biologically programmed to seek CO2, solution - more CO2. Am I on the right lines? Is it not possible that low levels of light and/or CO2 could be responsible for a plant making a straggly bid to get to the atmosphere? Is it not likely to vary from species to species depending on the environment they evolved in? Would an immersed plant with its leaves in the CO2 rich atmosphere not go stringy if deprived of light?

EI. Your tutorial says that 20ppm/week is the unlimited threshold dose for NO3. So that would mean in the case of the tap supply being 40ppm (mine is close to that) and a 50% weekly water change there would be no need to dose for nitrates?

You give the unlimited light threshold as 5w per gallon. Hang on that's not sounding so cutting edge! Is that your funny old tube thingies? How much light per watt? What shaped tank? What I'm trying to work out is amount of light - PAR or Lumens/Sq meter - that equates to your 5w/g. Sorry if its posted somewhere but I couldn't find it.

And, If I wanted to go for a system operating at say 50% of that threshold - given that there would plenty of CO2 and correct EI nutrition levels. How much light do I need?

All best Tony

Ps. If you have any video or photographic project in mind please message me. If I can help out I'd be happy to.


----------



## ceg4048 (31 Oct 2012)

tony456 said:
			
		

> Stringy plants. Here's what I think you're telling me with the links. Old school says - most aquarium plants are amphibious, they're biologically programmed to seek light just like a terrestrial plant, solution - more light. School of the avant guard says - they are biologically programmed to seek CO2, solution - more CO2. Am I on the right lines? Is it not possible that low levels of light and/or CO2 could be responsible for a plant making a straggly bid to get to the atmosphere? Is it not likely to vary from species to species depending on the environment they evolved in? Would an immersed plant with its leaves in the CO2 rich atmosphere not go stringy if deprived of light?


Well it's easy to make an argument for almost any parameter, but biological programming does not occur in the same way as we might imagine. There is a hierarchy of things that plants need and this hierarchy determines the plant response. There are also different mechanisms involved based on the particular need of a plant in a deprived environment. So we need to first understand the plant needs, the environment and then the mechanisms in order to unravel the mysteries.

To get a deeper understanding you have to study the article linked in the 7th post of that first thread I listed by the OP. I'll link to it again here. The article is entitled  Ethylene Sensitivity and Response Sensor Expression in Petioles of Rumex Species at Low O2 and High CO2 Concentrations

The problem in this hobby is that everyone automatically thinks about light first when they think about plants. They don't think that plants do anything but eat light. So that becomes their focus to the exclusion of all else. Very few people think about the fact that plants breathe. That they have a network of channels and that gas exchange in plants is as important as light. Plants deprived of the gasses they need die as quickly as those that are deprived of light. Without Oxygen a plant cannot burn the food it makes to feed it's cells. Without CO2 it cannot even make the food, the glucose that the cells need. Without these two gases therefore, it doesn't matter how much light is available. The plant will suffocate and starve very quickly.

The illusion of the overriding importance of light is made stronger because of the ease with which we ourselves can see light. We know right away the difference between dim and bright, but we can't see CO2 or O2. But try the following experiment:
1. Try closing your eyes for 5 minutes. Any effects? No?
2. Try holding your breath for 5 minutes. Effects? Yeah, I'll bet.

This experiment demonstrates the hierarchy I mentioned above. That we can do without light for quite some time in comparison to the length of time we can do without gas exchange. Even though plants are autotrophs, and even though they need light more than we do, the situation is actually quite similar for them in that they can easily deal with poor lighting but they cannot easily deal with poor gas exchange. Without excellent gas exchange, and without access to gases, light is rendered completely irrelevant.

Therefore, under conditions of poor gas exchange, the plant's response is to seek better gas exchange at all cost. At that point it really does not care about how much light there is because it is suffocating. The mechanism by which this happens is that the plant constantly produces very tiny amounts of a hormone called Ethylene, a HydroCarbon with formula C2H4, and which also happens to be a gas. The only gaseous hormone. The reason evolutionary forces developed a gaseous hormone for aquatic plants is actually ingenious. All gasses encounter a reduction in solubility and diffusion rates at 4 orders of magnitude in water. So the way that a plant is aware that it is in water is that the water will cause the gaseous hormone to diffuses slowly in exactly the same way that CO2 and O2 diffusion slows down. The same mechanism of slow Oxygen and CO2 transport which suffocates the plant also slows the diffusion into the water column of Ethylene, so the Ethylene concentration in the tissues builds up. Ethylene receptors in the tissues are then triggered and this tells the plant to use it's resources to extend the distance between the nodes - to elongate in order to get to the surface where O2 and CO2 are abundant.

When people flood a tank, they have absolutely no clue that what they are doing is suffocating their plants. All they can think about is pumping as many megawatts of light in some misguided concept of how plants grow. They do not realize that CO2 and Oxygen is 10,000 time LESS available in the water than they were in air. They have no idea of the C2H4 tissue buildup. So they never realize that  you need to inject high doses of CO2 and that you need to have a high mass flow rate over the tissue surface in order to carry away the C2H4 so that the concentration in the tissues do not build up and is carried away from the plant. That's one of the primary functions of high flow rates in a planted tank.

Terrestrial plants that elongate in deep shade is a completely different set of conditions, and the elongation does occur based on the higher proportion of Far Red wavelength (near 700 nm) that are prevalent in shade. This is a completely different set of environmental conditions and has nothing to do with flooded plants. So in that article the author talks about how an aquatic Rumex species responds according to the gases that are supplied whereas the non-aquatic Rumex species does not respond in the same way. The response of the aquatic Rumex to these conditions is how most all the aquatic plants behave under similar conditions. When your aquatic plants elongate therefore, it means that you should conclude that CO2 and flow is poor and the plant is responding to poor gas exchange. The Matrix does not teach you about this. It tells you to add more light but that is just another illusion.



			
				tony456 said:
			
		

> EI. Your tutorial says that 20ppm/week is the unlimited threshold dose for NO3. So that would mean in the case of the tap supply being 40ppm (mine is close to that) and a 50% weekly water change there would be no need to dose for nitrates?


The correct procedure is to dose the amounts given in the tutorial and to forget about what you think you have in your water. No one can actually measure the real NO3 levels in water unless they have access to advanced scientific equipment. Neither the municipality you get your water from nor your hobby grade test kit
can accurately give you these values so the best policy is to dose the suggested amounts of KNO3 powder. If at some point you wish to lower the dosages then you can do so easily.



			
				tony456 said:
			
		

> You give the unlimited light threshold as 5w per gallon. Hang on that's not sounding so cutting edge! Is that your funny old tube thingies? How much light per watt? What shaped tank? What I'm trying to work out is amount of light - PAR or Lumens/Sq meter - that equates to your 5w/g. Sorry if its posted somewhere but I couldn't find it.


I'm sorry but I don't know the answer to that question. No PAR readings were reported for exactly the same reason you gave in your post. Meters are expensive so everyone just muddles on. So few people have any idea about what PAR even is, much  less know what the values in their tanks are. Barr might have been using T5 fluorescent over the 20G tank. The whole point of the article is to demonstrate that increased light generates an increased growth rate with a corresponding increase in nutrient demand. He was not trying to determine specific lighting values or to correlate PAR values to nutrient levels. Besides, there is no real way of reproducing exactly the photonic conditions or to calibrate them on a curve. There are some charts however that plot T5 and T8 wattage against PAR and distance from the bulb. I'll have to search for those as they are very useful.



			
				tony456 said:
			
		

> And, If I wanted to go for a system operating at say 50% of that threshold - given that there would plenty of CO2 and correct EI nutrition levels. How much light do I need?


Again, you'll not find any chart that describes that. First of all, every plant has a different Light Compensation Point and they respond differently. Light causes radiation damage to plants, a phenomenon known as photoinhibition, which actually destroys their tissue structure. The ability of each species to repair the damage and to protect themselves from high light poisoning varies widely. What Barr mentions generally is that if you can measure PAR you can use a low stress setting to generate somewhere around 40 micromoles at the substrate, a medium setting would generate about 75 micromoles at the substrate and a high setting would generate about 100-150 micromoles at the substrate level.

These numbers show how wide a tolerance based on CO2 and nutrition plants can adapt to. So the question of "need" is irrelevant. More light generatse faster growth but it doesn't mean that plants under high PAR are any healthier than plants living under low PAR. That is THE misguided basis that people use to justify high light. Having lots of CO2 means that you can use even lower PAR numbers. So the only real "need" of a plant is to stay above LCP, which, for most plants is somewhere between 10-20 micromoles, which is very very dim. I saw a non-CO2 tank the other day in a dentist office, and it was so dim I couldn't make out the plants at the bottom of the tank. I had to put my nose right up to the glass to peer through the darkness It was a cheesy grolux 15 watt T8 and the tank was a hexagon just under 3 feet deep. I was able to make out loads of some of the most beautiful Anubius I had ever seen. Perfectly healthy with a waxy sheen and zero algae.

Asking this question about how much light you "need" is like asking how fast you need to drive on the road. There is no need.



			
				tony456 said:
			
		

> Ps. If you have any video or photographic project in mind please message me. If I can help out I'd be happy to.


Well what we really need is some photography tutorials, either equipment selection, post-processing using popular image software, or even tutorials on photographic technique would be useful, so that's the sort of expertise that would be useful for that section. If you think you might like to contribute in that way let any of the staff know. [/quote]

Cheers,


----------



## TopKat75 (31 Oct 2012)

Now thats a statement lol!!! Pretty much everything you need to know and why right there!!


----------



## tony456 (6 Nov 2012)

Clive thanks v much. I've really appreciated the depth and detail you've brought to this.

On the subject of light and CO2 - I hear you pal.

On flow rate - with you to point but, re hostile enzymes, wouldn't high volume of water change be more effective than washing the same water (and enzymes) around faster?

Nitrate levels and London water - I agree hobby test kits are hard to read but, when you have countless hobbyists reporting levels around and about 30 to 35 ppm can you assume they are all wrong, by the same amount and in the same direction? And when the water company (who have no incentive to overstate the figure) gives a similar level and, presumably, has the ability to measure accurately, is it not time to give this figure credence? I see where your hostility to testing and metering comes from but it seems that you are in danger of letting ideology overcome reason. How do you feel about thermometers, geiger counters, gps systems? I'm inclined to believe London tap water has nitrate levels north of 30 ppm and I can't see any reason not to account for that when considering nutrient levels in an aquarium.

Measuring light - I better tread carefully here! When I said how much light do I need, i confess I was being provocative. Sorry. I should have said how much light do I want and how do I know what that is? Given that different types of lighting produce very different amount of light per watt, that reflectors and lenses direct output, that a large tank may have different light levels in different areas and that not all tanks are the same shape, the watt/gallon thing is not very helpful. If I'm going to fork out on new lighting I want to know that it can deliver the maximum amount I'm ever likely to want. That doesn't mean I'd be hitting the plants with that 100% output. Its easy to reduce the light from a unit with neutral density gels or height adjustment, but you can't go the other direction.
So if we dump watt/g where do we go? Light output is measured in lumens, one lumen being the light produced by a single candle. The total visible light output (luminance) of a bulb is measured in lumens a bit like an engine has a given horsepower. More useful is illumination or incident light (light falling on a given object) it's measured in lux (lumens/square metre) and varies with distance from the light source. PAR is the proportion of Lux that can be utilised by plants (measured in some funny unit that I don't understand). PAR tells us a lot about how our plants will respond but it tells us less about what our tank will look like to us. Vice versa for lux. A light source with no green in the spectrum may produce healthy plants but they will look grey. If we're looking for a standard I'm inclined to think that the most useful measurement is lux. If we assume we are all talking about fixtures with a daylight colour balance of around 6000 kelvin I think its reasonable to assume that there will be a roughly consistent lux/PAR ratio. Lux ratings are available for most fixtures. PAR is obscure outside of UKAPS and some dope growers sites.

Photography - I'm better at video related matters than stills and I'm hopeless at what's going on in the domestic arena but will have a look at the forum and see if I can bung a thought in.

As for my inter galactic tank project. I'm some way off getting this off the ground so will content myself with some R&D on a small tank in the short term. I ran my last tank on an automated water change system swapping up to 20% a day. I'm interested in exploring a high water change and CO2, low additive and filtration angle.

All best Tony


----------



## ceg4048 (6 Nov 2012)

tony456 said:
			
		

> On flow rate - with you to point but, re hostile enzymes, wouldn't high volume of water change be more effective than washing the same water (and enzymes) around faster?


Yes, that's right, and that's another reason we suggest massive and frequent water changes and that folks should forget about the street corner myth regarding keeping tank parameters the same, because what that does is it keeps the same lousy pollution in the tank that kills the fish and makes the plants unhealthy.



			
				tony456 said:
			
		

> Nitrate levels and London water - I agree hobby test kits are hard to read but, when you have countless hobbyists reporting levels around and about 30 to 35 ppm can you assume they are all wrong, by the same amount and in the same direction?


Yes, they are all wrong, but NOT necessarily by the same amount and NOT necessarily in the same direction. And there is the rub. If they _were_ all wrong by the same amount and by the same direction, then that would actually be a GOOD thing, because that would mean it's possible to consistently calibrate the kits. If the error is a consistent known amount then it can be adjusted for. Think about your cameras. Have you ever had a camera body in which the meter consistently under or over-exposed? You wouldn't throw the camera away, you'd just figure out how many stops and in which direction an then you would simply turn the dial in the appropriate amount of exposure compensation, right? But what if the camera underexposed one minute then overexposed the next minute. What if the error was completely unpredictable? Would you trust that camera for ANYTHING? Would you trust it to make your living off of? Read this thread just to get an idea of how wacky NO3 test kits are=> viewtopic.php?f=11&t=16092




			
				tony456 said:
			
		

> And when the water company (who have no incentive to overstate the figure) gives a similar level and, presumably, has the ability to measure accurately, is it not time to give this figure credence? I see where your hostility to testing and metering comes from but it seems that you are in danger of letting ideology overcome reason. How do you feel about thermometers, geiger counters, gps systems? I'm inclined to believe London tap water has nitrate levels north of 30 ppm and I can't see any reason not to account for that when considering nutrient levels in an aquarium.


Firstly, we do not know by what method the municipality is testing, and we know that Nitrogen compounds are very difficult to measure, this is regardless of whether by titration or by ion selector probe method. This just happens to be a difficult parameter to measure because of the behavior of the compounds in an aqueous solution. Also, they did not measure their samples in your house. They also report a "Mean value" as well as the "max deviations" right? This implies that the values vary in the samples that are taken. In fact, the variations may be so wide that a higher number of samples must be taken in order to have the calculated mean value be statistically relevant. It is logical to conclude that the value at your house is not likely to be the same as mean value.

I do not feel this way about thermometers because the the thermal property and the behavior of materials is consistent. When you add/remove a specific amount of heat to/from an object the physical properties of that object changes in a consistent and predictable manner. The molecular structure, the density/volume and even the electrical characteristics, in metals for example, change in an exact, precise and predictable manner. Therefore you really have to be an incompetent thermometer maker to screw that up. 

Geiger Counters and GPS devices likewise operate on a consistent set of principles. These are Quantum Electrodynamic principles which are the fabric of our very reality. The behavior of the electromagnetic phenomenon is reliable, precise and consistent. We have empirical data which demonstrates exactly how these phenomena behave and how they interact with our measuring devices. We can even refine these devices to obtain greater accuracy as our manufacturing technology improves. 

Thus far, the behavior of Nitrogen compounds in water has eluded our attempts at inexpensive means of accurate or consistent measurements. To the contrary, and as illustrated in the thread linked above, NO3 test kits have consistently demonstrated their unreliability, and their only claim to consistency is the repeated abysmal failure when the hobbyists decides to trust their readings. Therefore they have proven themselves useless. My ideology is based on these proofs of failure. I guarantee you that




			
				tony456 said:
			
		

> So if we dump watt/g where do we go? Light output is measured in lumens, one lumen being the light produced by a single candle. The total visible light output (luminance) of a bulb is measured in lumens a bit like an engine has a given horsepower. More useful is illumination or incident light (light falling on a given object) it's measured in lux (lumens/square metre) and varies with distance from the light source. PAR is the proportion of Lux that can be utilised by plants (measured in some funny unit that I don't understand). PAR tells us a lot about how our plants will respond but it tells us less about what our tank will look like to us.  PAR is obscure outside of UKAPS and some dope growers sites.


Yeah, and that's why so many people have troubles. You really need to forget about lumens because that really doesn't help us. PAR and Lux, although they both measure light, have completely different emphasis. Lux and lumens have only to do with human perception of light while PAR is a direct measurement of the carriers of the electromagnetic phenomenon. The measurement is explained in the thread   http://ukaps.org/forum/viewtopic.php?f=21&t=21381  and a deeper discussion can be found in  http://ukaps.org/forum/viewtopic.php?f=50&t=6794

If you're not worried about intensity then all you need to do is to worry about what color bulbs will make your tank look good to you, and NOBODY can tell you that. If you like to red in your fish or to accentuate the red in plants, then get a red bulb and then balance it by having bulbs of other colorss. In the Lighting sub-forum have a look at the JamesC sticky where he shows images of various color T5 bulbs.



			
				tony456 said:
			
		

> Photography - I'm better at video related matters than stills and I'm hopeless at what's going on in the domestic arena but will have a look at the forum and see if I can bung a thought in.


Well, what about developing a tutorial about video editing? There are a lot of people who want to try their video and are already conversant in still photography, but video is still quite baffling.

Cheers,


----------



## dw1305 (6 Nov 2012)

Hi all,


> I'm inclined to believe London tap water has nitrate levels north of 30 ppm and I can't see any reason not to account for that when considering nutrient levels in an aquarium.


Testing for NO3 isn't really feasible without the dedicated equipment that the water companies use, but I would expect that the NO3 level of your water is at least 30ppm. The company should also give some sort of measure of the range of values tested (No. of samples, minimum & maximum values, "standard deviation" or "95% confidence interval").

In fact at certain times of year NO3 levels are probably much higher, as several of our water companies regularly exceed the 50ppm EU limit for nitrates. You can also assume that the water will contain considerable amounts of phosphorus, as "orthophosphates" PO4--- are added to all UK tap water. Calcium (Ca) also won't be an issue, potassium (K) levels are more of an unknown, and magnesium (Mg) levels are likely to very low, largely due to the geology of London Basin. Again the same applies to the other micro-elements, it is likely that some will be in excess and some will be deficient.

The idea behind EI is that levels of nutrients (including carbon (C)) are non-limiting, and productivity is governed by light input, with PAR driving photosynthesis, and the photosynthetic rate governing the requirement for all other nutrients. 

EI is not a method I'm ever going to use, but because of the need for nutrient levels to be non-limiting it doesn't matter what the levels of nutrients are in our starting water, we know by adding the correct level of EI nutrients *we will have enough*, and it doesn't matter if we have an excess.

Because we can't accurately test for a lot of nutrient levels (and this really is true, I have access to a £1000's worth of analytical kit (AAS, HPLC, GLC, ion selective electrodes, bench pH meters etc.) and to colleagues with many years of technical expertise, and I still can't tell you what the parameters of the tank water are), we add all the nutrients required, then we don't need to test, even if we could get accurate repeatable values.

cheers Darrel


----------

