What is happening to my stems (now with pics)

[Hooky]

Hi all could someone help me understand / establish what is happening to my stem plants. My Hygrophila polysperma stems are growing thin as well as very thin leaves this seems to be an issue the other stem plants in the tank. Today I have even noticed that some stems are rotting and disintegrating.

Lighting is two t5 28w for 6 hours a day currently dosing 3ml TNC liquid carbon and 4ml TNC complete daily. Tank measurements are 80X30X50. Substrate is scrapers soil roughly an inch and half deep.

I will try get some pics up when I am back home but does anyone have any ideas why I keep failing with stem plants?

 

[Tim Harrison]

Hi, good quality images will be a great help in diagnosing what's wrong, including a FTS.
Can we also have some info on the output and flow created by your filter as well.

 

[Hooky]

I will try get some pictures up tonight for you but the quality isn't going to be the best will be off iPhone.

The filter is the stock juwel filter for the Rio 125, I think this is rated at 600lph. In hindsight I now wish I had ripped the thing out and gone for a decent external, but the plan was an easy low tech set up and didn't expect these issues.

 

[Tim Harrison]

OK, I think you may have a problem with flow and distribution of CO2.
Using the 10x flow bench mark you really need a flow rate nearer to 1250 l/hr.
Also, the flow from a Juwel in-tank filter is fairly diffuse as well; there's no directional flow, which doesn't help either.
And whilst LC is OK it doesn't yield results anywhere near as good as injected CO2. So I think that maybe the root of your problem, especially considering the light intensity.
Btw if you're dosing LC your set up isn't low-energy, it's considered high-energy.

 

[Hooky]

Thanks Tim - I actually only started spot dosing LC to deal with some BBA, but have since started to dosing to try help improve the growth of the plants. If I stop dosing LC will this have any positive effect? And what are my options without ripping out the internal filter and going external ?

 

[Tim Harrison]

BBA is often a sign of unstable CO2...but to ensure we've the whole picture we'll still need those images.
If you want to pursue the low energy route, a light intensity reduction to one 28w bulb is perhaps a good place to start.

 

[Hooky]

Didn't get chance to take any pictures last night, but will defiantly get some up for you guys to take a look at when I get home from work. If this is largely a circulation issue could i not add a small circulation / powerhead at the opposite end to the filter to increase flow? The crypts in the tanks seem to be doing fine its just seems to be all the stem plants that I am having issues with.

 

[Hooky]

apologies for the poor quality pictures but can anyone tell from these what might be the issue: