Experiments And Observations - Comparing Notes On Planted Tanks

I thought it would be really interesting to compare notes on our experiences with planted tanks to see if we can pickup any tips from each other.

I'm going to try and kick things off from my own observations when things havent neccessarily gone to plan in my tanks more recently.

1. Fluctuating co2 levels causes algae
This is a fairly established rule but not one I'd come into contact with properly until recently given my tanks are all low tech. What happened? I got half way though a water change and got distracted with my son... Result? Tank was left for an extended period only half full. Firstly just to say that the fish were fine! But what I did observe was that a) the submerged growth on my crypt balansae did not appreciate the change of environment (probably including a drop in temperature and chamge in light lwvels alongside obvious loss of humidity). Crypts are  well known for 'melting' when firat planted as they transition from their emergent growth form (above water) to a submerged growth form. It appears that the opposite is also true (though I admit this seems obvious now I've written it, I'm not sure many aquarist experience it this way round). Further to this the bolbitis got covered in hair algae. This was no coincidence. The tank had run almost algae free until this point, with low lighting and no fertilisation. No further problems were experienced either. Once infected plant mass was removed the plants grew super well again this leads me to my next point...

2. Lots of filtration bad in a planted tank?
So I got the pipe cleaner stuck... couldn't get it out... it was Sunday evening... little one needed to go to bed... filter got turned back on and it got left (there seemed to still be a reasonable flow)... at the end of the working week I went to inspect jt and the flow had reduced significantly to a trickle. Needless to say with more time in my hands I got the pipe cleaner out and things were restored back to normal. What I discovered was that the plants had shot up over this week. Because the filters function has been impeaded and there was more nitrogen compounds around in the water the plants had kicked in and kept the fish safe, growing merrily away. So this leads me to think that lots of bio filtration in a planted tank may not actually be beneficial. That said... many recommend lots of it in aquascaping. We need to bear in mind though that this advice comes from high tech set ups where  they dose ferts using the Estimative Index. This is a methodology whereby all compounds get dosed in excess to ensure no deficiencies. The excess is managed at the end of the week with a very large water change. In a low tech setup we tend to dose micro ferts only (no nitrate and potassium) or low volumes of a complete fertiliser as plant growth is slower. Now personally I don't want to dose more nitrate containing fertiliser due to fish health concerns BUT it would seem that if I was to reduce the amount of filter media in my filter I might be doing my plants a favour as ammonia will be used by the plants instead. I'd need to keep an eye out for potassium deficiencies (yellowing of tips or edges and holes in leaves) but its something i think i might give a go... in a more controlled way next time!

3. Filter bacteria don't just live in the filter
Again this one is fairly well established but I believe I now have evidence for it... In my Betta tank I have an air powered sponge filter. Its a custom made thing. Unfortunately I discovered that the air stone can slip away from the base of the up tube and therefore affect flow through the sponge.  Then filter is well hidden behind plants and hardscape so when this first happened I noticed it because i noticed what i thought was a diatom outbreak. It got worse and then I realised it wasn't diatoms, it was not sticking to surfaces as such but growing into fluffy mounds of the stuff on the substrate for example I'm fairly confident now that this was what we might call filter bacteria.but growing in the tank to take the place of those in the filter sponge which were now not receiving the flow they needed to deal with the wastes in the tank. I was fortunate to have a heavily planted and hardscaped tank with lots of surface area in it so that the bacteria could quickly multiply to deal with the filter issue and protect the Betta fish.  Water tests showed no problems. When i siphones the masses of bacteria out and reset the filter, the next week everything was back to normal with no side effects, I believe this goes some way to prove the theory.

Overall message - tanks are hugely more robust with plants in them

So what have you all discovered over time that has helped you grow plants more successfully?

As a side issue, so-called filter bacteria are actually present in the substrate in greater levels than the filter, together with a whole host of other micro-organisms.

Do you mean in general Sue, or in your Betta tank? In a ‘well stocked’ tank there are far more in the filter. Easily tested by trying to cycle a tank with substrate and no filter. Unless there’s an undergravel filter in place there simply isn’t the oxygen flow within the substrate to support many aerobic bacteria, and they will only be on and near the top.
A canister filter can support enough bacteria to handle a few thousand small fish (an 8” fish being equivalent to c500 1” fish, and so on).

I’ve never had a high tech tank, and plants have always really been secondary to the fish for the most part, but I know that a change in any parameter can affect plants and especially algae - a change in amount of flow, temperature, pH, hardnesses, light wavelength or intensity or duration, etc.

The prevaling belief used to be that it was the slightly higher CO2 levels and lower O2 levels that were beneficial to plants with low flow/filtration, but the presence of ammonia sounds just as likely.

It’s amazing that just a few hours of low water level can have such a big effect. I’ve never made that connection. Matt how long was it low for? Did things all revert back again in the end?

I’ve been keeping algae as long as I’ve been keeping fish. I prefer low lighting and I’m on intimate terms with quite a few different species including the brown diatoms. But I’ve no idea how to get rid of any except by changing something and seeing what happens. For me, brown diatoms like low lighting, and the black tufts like tanks with very low lighting, and low flow. Although other factors are no doubt also involved.

With terrestrial plants I’m quite green fingered, and they need everything - light, temperature, watering, food, humidity - to be in an acceptable range. If any one of them is off, the others are too. For example if a plant isn’t getting enough food but the other parameters are good, this also means it’s getting too much light and water (for the amount of food it’s getting). If it’s not getting enough light then it’s getting too much water and food for the amount of light... etc.

I assume aquatic plants are probably similar, and that everything needs to be balanced, within range?

Then I discovered that plants need red and blue light to grow properly, with red light being more important, so I finally bought another light, an Aquael Leddy clip on light, which had red, white and blue LEDs. The plants are now growing again, and the new bit of water sprite is thriving.

Hi @Sue

That is an excellent example that you have given concerning the importance of light spectrum. On another forum that I use, I keep hammering on about the importance of light spectrum. Many aquarium lights are not optimized (or even usable) for planted tanks. This is a topic that interests me greatly. I can measure aquarium light spectra as I have recently acquired a spectrometer.

JPC

That's interesting, thanks,  do you think they could still be using the ammonia/nitrogen?

Ahhh I see what you mean... it could be that, but I'm still currently thinking diatoms or bacteria, it's brown in colour and not the same texture. Im familiar with the fungus that grows on wood... its yucky stuff!!! 

Could be! Could I have got more when the filter wasn't working as well, even though flow was largely the same?

I believe mulm as Humpalong suggested is probably the right answer. However through my research it does look like mulm can support growth of biofilms including bacteria and fungi... it's the same as adding leaf litter to a biotope aquarium and can support higher species too e.g. daphnia. Mulm is not all bad (depending on your set up) it seems.

What I was seeing visually supports the biofilms (bacteria) hypothesis, texturally it did not appear to be a fungus. I have noticed a plant towards the rear of the aquarium has melted away recently and the slope of the substrate would lead debris to accumulate in a similar spot. This is likely root cause of the mulm, on which the biofilms grew.