GillesF said:
Ceg, thanks for the info, I'm definitely using some of this for my blog. Just a quick question: is it always better to have spraybars at the back instead of left or right? I think that my H. Callitrichoides didn't want to grow due to bad flow and not too low light.
Hi Gilles,
You're very welcome. Generally, I've found that it's better to mount the spraybars along the back wall because the short distance to the front makes better use of the flow energy. I imagine that if the flow is strong enough then mounting it on the side wall would be OK. As with all things there are mitigating circumstances. In very small tanks for example it doesn't really matter which wall the spraybars are mounted on, however, I mostly deal with large tanks and so it makes an enormous difference because the distances are large and the resistance to flow greater. Have a look at the thread
http://ukaps.org/forum/viewtopic.php?f=37&t=3827 for examples of how I prefer to mount my spraybars.
gargamelcz said:
But I am still curious how come, that this tank:
http://www.akvarko.cz/akvarium.php?nadrz=2488 is so succesful, even though there is no flow. You said, that's all about luck mostly, but can you explain reasons, why this particular tank is succesfull? I'll translate something about that tank:
tank volume 720 litres
light 0,4 W/l T8 tubes
volume of filter - 60 litres and flow rate only 400 litres per hour!
no sprabarr, nor powerheads
temperature 28° to 30°C.
Fertilization: PPS
Small amount of CO2 - max 2 bubles/sec.
Water changes once a week 100 litres.
It's very difficult to assess the performance of any tank from a distance, especially if we do not know the hobbyist and if we are not there to determine exactly what was done. All we have are a few statistics and we must analyze based on the truths that we know. Also, remember that what you see in the photo is a finished product. We do not know (or at least we can't tell if we don't speak Czech!) what has occurred up to the point where the photos were taken. How long did it take to achieve the finished product? What problems did the hobbyist have along the way? How were the problems (if any) solved?
let me tell you another secret illusion of the plant hobby. The water column is only one method to fertilize plants. The other method is the sediment. Plants can and do use nutrients from both locations. I often see where people talk about lean dosing but they are using an enriched sediment such as Aquasoil Amazonia. Few people realize that Amazonia produces a sediment nutrient concentration of up to 100X EI water column values. So the sediment can have almost a 2000ppm Nitrate levels. Even if a sediment is not enriched, with time, food, plant matter, and residual quantities of dosing enter the sediment and accumulate so that the sediment becomes enriched. Nutrients can then leech out of the sediment and even fertilize plants that are not rooted.
So just imagine, even if you don't dose very often, but if you feed the fish, urine, feces and uneaten food can still produce NPK. If the tank is sufficiently aged and if there is enough organic matter in the sediment the bacterial action in the sediment produces CO2 which results from respiration of the bacteria in the sediment. this CO2 can augment the CO2 being injected.
We can see that the lighting is not outrageous. It's just under 300 watts -
but this is T8, not T5, and we do not know the PAR values but we do know they won't be as high as what's in your tank. This is therefore a low stress tank. This is completely consistent with what we know to be true about plant growth.
As I mentioned before, we do not know what kind of water is being used. I do know that Czech river systems are typically over low solubility sediments such as granite, and that the waters are generally soft and with low mineral content. That's why Czech Pilsners and Lagers are among the most excellent in the world, but it's not clear if that is true in
this particular case.
It's not my intent to belittle or insult the owner of those tanks by implying that it was all just due to luck. That would be totally unfair. They are absolutely beautiful and very well executed tanks. The owners are certainly excellent hobbyist. But what I am saying is that sometimes people do the right things for the wrong reasons, and that is what I mean by luck. For example, I see a lot where people do frequent water changes thinking that they are "getting rid of Nitrates". As it often turns out, the water that they use is unwittingly high in Nitrates and the tap water is high in CO2, so what they are actually doing is to provide clean water, which plants love, add Nitrates which the plants have consumed, and replenished CO2. The plants do well but, they conclude that it's because they followed a strict policy of "keeping Nitrates low." Nitrate test kits are terribly inaccurate and it can easily be that the test kit reads low when the Nitrate value is actually quite high. As a result, it becomes very difficult to convince these people about the truth because they put their trust in events that may be coincidence, and if the coincidence happens to be in their favor then they are lucky!
When you set up a tank, if you don't put too much pressure on them to grow they can adapt to the condition. For example, if the lighting intensity falls slowly, plants have the ability to increase the "population density" of the chlorophyll in the leaf. That means more pigment cells per unit volume. More density makes better use of less light. If the light falls off slowly the pigment density change has sufficient time to be performed. We can then slowly increase the light intensity and we will see that the density of Chlorophyll is slowly reduced as a result. But if these changes occur too rapidly, the plant cannot respond with enough agility to compensate and it may become damaged.
The same happens for CO2. If we slowly reduce the CO2 level in the tank, we will naturally see a decrease in growth rate and mass but the plant will become more efficient at gathering CO2. Plants in high CO2 tanks are extremely inefficient because there is so much CO2 available that they use their energies to accomplish other things such as producing flowers. The problem is that if there is a sudden downward change in CO2 they are unable to make the adjustments quickly and often starve because they have not produced a sufficient quantity of CO2 uptake proteins to be able to deal with the sudden loss of CO2. This means that the same plant can either fail or prosper depending on the
rate of change of environmental conditions. it is not necessarily because of poor conditions that they fail. If they have had the opportunity to adapt to the low flow, low CO2, low light conditions, then of course they can do well.
That's why it's not easy to look at a picture and to immediately assess why a tank is in good shape. The fact is that we know the truth however. We know that nutrients cannot cause algae because we add very high nutrient levels and we get high growth and excellent health. We know that adding high flow helps the plant grow. We can see the results, and we know that these are the typical cases and if you follow these general rules you have a better chance of success than relying on the reverse.
Have a read of the threads for more information:
Why dont nutrients cause algae?
Do excess nutrients = algae? Is it possible to "know"?
Cheers,
