View Full Version : Deficient Rotala? Very low GH, KH. CO2 problems?

07-10-2010, 08:47 AM
Hey everyone. :D
So, it has been a while since I have had a planted tank. Previously I had mostly java moss and java fern and never worried much about lighting, water parameters, CO2, etc. However, recently I spotted some beautiful magenta rotala at my LFS and couldn't resist. I bought approximately 12 stems, which are currently paired and burried an inch or so beneath the gravel in a 10 gallon guppy tank. They spent about 2 weeks under incadescent lighting before I broke down and bought 2, 15 watt full spectrum compact florescents. It has been another two weeks since the lighting change and they are not looking well. The red coloring has faded mostly to orange, and there is some leaf loss and brown spots, but somehow they are still managing new growth. I'm generally worried the CO2 levels are causing this, but am not sure.
The light is on a timer for 10 hrs a day. The tank has been running for more than a year. I do a 25% water change once per week and vacuum the gravel every 2 weeks. I do a small dose of flourish once per week after the water change. There is decent sized peice of mopani driftwood, and there is very little water disturbance. I'm using some sort of ol' black bio-filter. :D

PH: before light 7, after light 7.4
Nirate: ?
Nitrite: 0
KH: 3
GH: 2
CO2 levels: 4-10

So, basically I am assuming that this is CO2 problem, as the macro's should be fairly plentiful from the guppies. Is there any way to raise the KH and GH of the water without raising the PH? I've heard seashells or coral will raise the KH GH and PH? And tannins from driftwood will lower PH? So, if I were to add seashells to the filter, and newer piece of driftwood still leaking tannins I would have a rise in GH and KH, but PH should stay around the same?
Also, by raising my KH "naturally", will this allow for a higher CO2 level? Or should I be adding a DIY or hagen CO2 unit or such?

Thanks in advance!

07-10-2010, 02:33 PM
You should check out this page. http://www.fishchannel.com/freshwater-aquariums/planted-tank/co2-basics.aspx
There is a great chart that I have found helpful for situations like this.

In your case if you were to just add some crushed coral to your mix your KH would likely increase and maybe bring your pH up even higher, although it can be difficult to anticipate where exactly your pH/KH will equalize.

You can try adding more CO2 to the system but I would go very slowly. You might also want to try using a different fert. Flourish is good but it's generally forumlated for green plants I thought. You might want to go with something a little more general and see if that works better before you go messing with water chemistry too much.

Lady Hobbs
07-10-2010, 02:46 PM
I tried it before and got little results. I tried it again in a better soil mix and now have a very nice plant. I also started dosing with iron which gave me better, thicker stems and no leaf loss at the bottom. I do not have great color due to using low-lights but still it's a nice plant that reaches the waters surface.

Rotala may not be the plant to use in gravel. It has fine roots that need to spread. I don't see gravels as conducive to good plant growth in hardly anything, really.

07-10-2010, 04:04 PM
Rotala may not be the plant to use in gravel. It has fine roots that need to spread. I don't see gravels as conducive to good plant growth in hardly anything, really.
That's interesting that you say that. I've used plain gravel in all my tanks and had very good luck with my plants. I had a huge growth of dwarf rotala in one of my former 29G tanks that grew for a few years before I disassembled the tank.

Lady Hobbs
07-10-2010, 04:07 PM
Not saying people haven't use it successful but in many cases, gravel just doesn't work especially for fine rooted plants and stem plants. It's hard for roots to grab hold of anything in gravel and especially larger gravels.

07-11-2010, 02:06 AM
I'm not too thrilled on the idea of dosing iron as I was planning on getting my hands on a few red crystal shrimp from a friend and putting them in there, considering it is my only planted tank. I have an new barebottom 20 gallon cycling with fry right now that I may eventually move my rotala into and aquire a few more plants. The gravel I'm using is quite fine around 2-5mm. I'm not fond of messy substrates. I may try adding a small 1L bottle for DIY CO2. What do you reccommend to catch the CO2 in the tank for absorbtion. It's only a ten gallon at the moment. I was thinking some sort of jar on an angle?
Thanks so much. :)

07-12-2010, 11:31 PM
Iron is a necessity for red plants and plants in general. The main supplements you need to dose are Iron, Potassium, and Trace from the seachem flourish supplement line.

As long as you don't overdose, your shrimp will be fine. If you are worried about a concentrated amount hitting your shrimp, you could always dilute it and use a drip method to dose your tank. All red colored plants need extra iron though.

I would also recommend putting your light on an 11-12 hour cycle.