Dwarf Sagittaria dying

bsquizzato · 05-09-2008, 03:37 PM

For months my Dwarf Safittaria was thriving in my planted tanks, spreading runners, lots of new growth, etc. Now the dwarf sag seems to be dying in both of my planted tanks that I have it in, and my tank params have not really changed.

I'm wondering if the main reason is that my lights need to be changed? I have had the same compact fluorescent now for maybe 10 months, is it time to change it?

mralgae · 05-09-2008, 05:40 PM

hi & welcome to FTF.
when you say dying how exactly do you mean?can you describe what the plant is doing and how it looks.
also you say your tank stats "havent really" changed which leads me to believe they have chnged in some way.
can you post the tank stats you have.

bsquizzato · 05-09-2008, 10:55 PM

Thanks... I'm not really new here just haven't posted in awhile..

By saying my tank parameters are the same I literally mean nothing has changed. The routines I do to keep water temp, PH, KH, GH, etc. etc. at the same levels has not changed. My fertilizer routine has not changed, granted I've probably slacked off occasionally, but I don't think nutrients ever bottomed out.

The sagittaria as well as my amazon swords just seem to not have any new growth, and the plants' leaves are essentially just kind of turning transparent one by one and then beginning to decay. The swords never grew rapidly but they would get new growth, and like I said the sagittaria was thriving and spreading. So I'm thinking this would be due to the light bulb being old and weak? It's a 65W compact fluorescent 10000k, and it's been in use about 10 months.

I just want to see if anyone else has experienced sag just suddenly dying.

Meanwhile, other plants like rotala are doing fine and of course crypts are doing fine.

Jay · 05-10-2008, 07:06 AM

Hey bsquizzato...long time no see

IMO the light could be an issue, I change out my compacts yearly. Dwarf Sagittaria, while an easy plant, does require a minimum of 2 wpg of consistent full spectrum light.

I do not remember if you are injecting CO2. If you are, I would check both the amount (should be up in the 35 ppm range) and the circulation, making sure the Sagittaria is getting its share. If not, I would try Excel on a daily basis and see if conditions improve.

I know you said your fert routine is consistent, but IME both the Sag and Swords are heavy users of NO3 and PO4.

Jay

bsquizzato · 05-10-2008, 07:53 PM

So I just tested nitrate in the tank... it's like 40ppm, maybe higher. API Nitrate test kits do kind of suck though, but it was definitely not this high in the past.

So clearly something is limiting further nutrient intake... I think maybe I should get a phosphate test kit.

So I was reading online, and Rex Grigg seems to feel that needing to replace CF bulbs every year or so is a myth and he thinks you can just use a good quality CF bulb effectively till it dies. So maybe it's not the light.

Jay · 05-10-2008, 08:32 PM

A good water change will fix the nitrate level

Yeah...I kinda agree with Rex and CF's, we are not talking about super high light needs here.

I tend to agree, something is being overlooked in the nutrient CO2 department.

Jay

bsquizzato · 05-13-2008, 03:45 AM

Well, this is interesting. After close to a 50% wc today I tested my water, and Nitrates are probably about 30ppm, but I also tested phosphate and that is somewhere between 2 and 5ppm, maybe something like 4ppm. I don't know why that is so high. I shouldn't even bother dosing this stuff for now.

Would moving off excel to CO2 make nutrient intake more efficient, despite my lower wattage? It seems like that is the limiting factor...

Jay · 05-13-2008, 06:07 AM

What is your watts per gallon ratio?

You could back off the PO4 a bit 1-2 ppm is good for light in the 2-3 WPG range.

I am starting to lean in the direction of light, specifically not enough to stimulate sufficient uptake of nutrients. The nutrient levels you mention are sufficient for a heavily planted high light tank. If you increase the light, then the injection of CO2 will give you good rapid growth. I think the sag. is dying because it cannot uptake enough nutrients the limiting factor being light energy.

I should have asked that question earlier on.

Oh well, we are narrowing down the limiting factors.

Jay

bsquizzato · 05-13-2008, 03:50 PM

I've got 65W over a 29gal, so 2.24 wpg. I've thought about getting one of those coralife 130W 30" fixtures, but we'll have to wait on that for awhile, because then I need to go CO2.

The dwarf sag was growing well before though. I just need to order a new 65W bulb and see what happens now I think.

Now that I think about it, I've got my old 20W light fixture. If I also put that over the tank, I'd be close to 3 WPG. Could I still manage that with excel?

Jay · 05-13-2008, 05:24 PM

Sure...the Excel will still work for you. I am concerned that the plants may have given up and gone into permanent decline. You might want to re-establish control and replaced them.

This same problem happens to me occansionally with Bacopa.

Jay