Potamogeton Gayii Has Suddenly Turned Brown!

So this plant was happily growing up towards the light and a couple of days agi the tips of one stem touched the surface. Since then it has started turning brown and looks like it is dying. I don't know what the problem is I haven't changed anything. Is there anything I can do to save it?

It's gone from looking like this


To looking like this


Tank details

Juwel Rio 180 with internal filter removed
Tetratec EX700 external filter
Hydor external heater running at about 28 degrees C
Currently have about 20 - 25 Co2 bubbles per minute being diffused into the inlet of the filter for the time being
No CO2 reading yet as my drop checker has not turned up from ebay yet
Dosing Seachem Flourish and Excel once per week as per bottle instructions
Substrate is plain old Argos playsand
PH 6.8
Yesterday I changed the standard Juwel Tubes to two 30w Arcadia Classica Daylight (apparently these are the same as the Freshwater ones)
Both the tubes have arcadia reflectors on them.

Other point to note is the tank is currently in the middle of a fishless cycle.

Oh that's a shame, it looks great in the first picture.
Everything sounds fine, it's a good set up. However on a 180litre I would expect perhaps 90-120 bubbles a minute to get the water to 30ppm of CO2. Might be worth investing in a pressurized system, you'll never look back.
Also, you are dosing once a week, which isn't that good despite what the bottle says. The plants need a constant supply of nutrients throughout the week, not a load of nutrients on the first day. The plant looks like it needs some nutrients. For example, I would personally dose 10ml after a 50% water change on day 1, 5ml on day 3 and 5ml on day 5. With t5 lighting and CO2, your're going to need the nutrients, trust me.

RadaR said:

Oh that's a shame, it looks great in the first picture.
Everything sounds fine, it's a good set up. However on a 180litre I would expect perhaps 90-120 bubbles a minute to get the water to 30ppm of CO2. Might be worth investing in a pressurized system, you'll never look back.
Also, you are dosing once a week, which isn't that good despite what the bottle says. The plants need a constant supply of nutrients throughout the week, not a load of nutrients on the first day. The plant looks like it needs some nutrients. For example, I would personally dose 10ml after a 50% water change on day 1, 5ml on day 3 and 5ml on day 5. With t5 lighting and CO2, your're going to need the nutrients, trust me.

Click to expand...

I would love to get pressurised Co2 but that just isn't going to happen for a while as I already spent too much cash on this tank recently. I have upped the bubble count to about 60 now thanks to another yeast mix bottle, so maybe that'll help. I've also just received my drop checker, so we can get some idea whether I'm getting enough CO2 into the tank. The trouble with doing big water changes is that I can't really do any at the moment because of the cycle process. Once this finally finishes - it has stalled twice on me so far - I am looking to go down the EI route. The lack of water changes makes me nervous about putting too many nutrients in as I don't want a massive algae attack. Already have a few traces of algae around. Would I still be OK to add nutients more often than once a week without the water changes?

By the way, I just tried the second link in your sig and it doesn't seem to go anywhere.....

Good news about the CO2.
Ah yes I see. Water changes would dilute the ammonia and therefore render the cycle useless.
However, if you plant heavily (I don't know how heavily you've planted because I havn't see a full tank shot), covering 75% of the gravel with plants then you don't need to put a great deal into cycling. Don't get me wrong, cycling is probably the most important thing in fishkeeping, but plants make it so much easier. Plants are magnificent at absorbing ammonia, nitrite and nitrate. Plant heavily enough and all of these should be aborbed, therefore if you introduced a small number of fish they wouldn't die from poisoning because the plants are soaking up all the nasties. As the plants soak up the compounds and are provided with light and CO2 then they grow and absorb more. Over time the filter will colonise with bacteria too. That's some real efficient biological filtration you've got now.
So, if you've only got a few plants, then try invest in some more to cover around 75%.
Good, fast growing plants include:
Hygrophila species
Ludwigia species
Rotala species
Egeria species
Brazilian Water Ivy
Small Ambulia
Mexican Oak Leaf
Water Sprite
Hornwort
Floating plants (careful they don’t block too much light)

Greenline is a good online store that sells good, cheap plants ideal for this job.
Once you've planted up then I don't see why you couldn't get your first fishes.
You are then open to do full EI. In which case just refer to the helpful EI pinned thread and you should be away. It details how to carry out EI and the required nutrients you'll need. You can then safely do those 50% water changes each week without the fear of ruining the cycle. Not to mention you'll be on your way to a algae free, planted tank.
You've mentioned that you've spotted algae and that it's down to nutrients. Infact, nutrients don't create algae. Nutrients supply your plants with food and the plants out compete the algae. It's my belief that the algae you've seen is because of the ammonia that exists during the cycle period. It will go shortly once you introduce more plants.
Hope I've written clearly enough for you to understand.
Thanks for pointing out the fault in my sig. It used to work however the forum did have a re-vamp between then and now. Anyway, it's fixed now.

Wow that' s a lot of information, cheers for that! I am not all that heavily planted yet, although I plan to increase the number of plants a fair bit. The tank is actually double aspect in that it is visible from both front and back. This makes it more difficult to plant heavily as it has to look good from both sides. The tank is set-up in a custom made cabinet where there used to be a set of double doors to another room. I will post pics when I'm happy with how it looks.

I have put a hold on buying new plants until I can get the ones I have all happy and growing well. As you can see from another recent post of mine, this isn't the only plant I have had issues with.

[URL="http/www.fishforums.net/content/Plants-and-Planted-Tanks/242138/Plants-Dying-In-Middle-But-Growing-At-Top/"]http/www.fishforums.net/content/Plants-a...Growing-At-Top/[/URL]

On a curious note, if adding nutrients does not encourage algae then why is there so much fuss about dosing them correctly? Even with EI you have to regularly change 50% water to stop the levels getting too high. The fishless cycling thread I followed to start my cycle did state that lots of algae could creep in during the cycle process, so you are probably right about the ammonia causing it. I'm clinging on to the hope that the Potamogeton Gayii will recover, but it looks pretty unhealthy right now. I lost another batch in exactly the same way and when I removed it the whole lot just fell apart and made a right mess of my tank!

Thanks for providing me with so much help

razorkai said:

Wow that' s a lot of information, cheers for that! I am not all that heavily planted yet, although I plan to increase the number of plants a fair bit. The tank is actually double aspect in that it is visible from both front and back. This makes it more difficult to plant heavily as it has to look good from both sides. The tank is set-up in a custom made cabinet where there used to be a set of double doors to another room. I will post pics when I'm happy with how it looks.

Click to expand...

Wow, that sounds fab!

razorkai said:

I have put a hold on buying new plants until I can get the ones I have all happy and growing well. As you can see from another recent post of mine, this isn't the only plant I have had issues with.

<a href="http/www.fishforums.net/content/Plants-and-Planted-Tanks/242138/Plants-Dying-In-Middle-But-Growing-At-Top/" target="_blank">http/www.fishforums.net/content/Plants-a...Growing-At-Top/</a>

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Ah yes. How odd. Lighting is fine, so it must be the combination of low CO2 and nutrients. As for a diffuser, the only ceramic disk diffuser I know that works with DIY yest CO2, is this one. It's just a shame that it says for aquariums up to 60litres, however I don't know another ceramic diffuser that will work with DIY because the pressure to get through that disk is high and most DIY can't handle bigger diffusers. It should still benefit you though. It will take for the pressure to build up and then you should see a mist of bubbles coming out of it which hopefully will get blown around your tank, diffusing CO2.

razorkai said:

On a curious note, if adding nutrients does not encourage algae then why is there so much fuss about dosing them correctly? Even with EI you have to regularly change 50% water to stop the levels getting too high.

Click to expand...

Honestly I don't know why there is so much "fuss" about dosing nutrients correctly. That's a question that someone with more knowledge could help you with. The 50% water changes with EI are more of a way of "reseting" the tank and allow us to know how much nutrients is roughly in the tank. Hence "estimative" index..It also gives a chance to stablise any KH/GH levels.