Stunted Ludwigia

My Ludwigia stopped growing a few weeks ago and started losing it's bottom leaves. It wasn't great before this, but not as bad either. (It used to grow like a weed with no extra KNO3) I normally only add K, CSM, small amounts of KNO3 and Magnesium. I add PO4 when I think to check it. The fish and food usually add enough KNO3 and PO4 for my liking.

When I noticed that the Ludwigia were suffering I tested the PO4 and topped it up to 1 ppm+. The next day the one plant spouted a bunch of new leaves but did not do much else. I also noticed some round holes at the edges of the leaves about this time. Since the PO4 was still good I assumed that the growth spurt was due to extra Potassium in the KH2PO4. So I added some extra Potassium and the leaves seems to fill out and get some of their sheen back. But still no growth, the plants are about as tall as they were three weeks ago. I used to have to top and replant them every week.

My GH test kit seems to be toast (KH is 7) unless GH is over 30. The only other thing I can think of is that the new lights (Coralife 10K) which replaced some generic 10K are crap. One of the old lights was burned out and another was fading, so I replaced with the Coralife Super Daylight. I also run some 6700K morning and night, but total watts is 400, so I don't run them all at once. I may pump up the light for a while to see what happens.

Other factors, Anubias growing like a weed, Sword is huge although maybe a little pale. CO2 about 30, PH is 6.8, Iron is .25, Calcium is NFI but I have Aragonite in the filter.

I'll be going to an auto-doser one my DIY testing is complete.

 

I added extra Mg the last two weeks just in case. Plants look healtier but not growing. I've got a new GH test kit coming tomorrow along with a new diffuser.

 

Heater blew out about two months ago, so tank is probably about 78 with the new heater vs. 80 with the old heater. Sword is always growing, now more than half the tank. Altough it has not spawned lately. Anubias is growing like a weed, but this is offset greatly by the reduced Ludwigia. Ludwigia would easily grow to 2' before I could trim it before.

CO2 runs through the UGF using two penguin 660Rs, so I'm wondering if the gravel has gotten clogged and the CO2 has gotten localized. I'll try playing with the flow to see if it makes a difference. UHF will be going with the next tank upgrade.

 

Yes I have two Penguins (660R) with venturis blowing water uder the gravel plate, RUGF. The CO2 feeds into the venturis. Although I find it's either one pump or the other doing the sucking, they don't seem to share well. I've read lots of horror stories about this setup, but it's always worked for me. I can easily get good CO2 levels and dispersion is normally fairly even. I do occaissonaly get CO2 farts if I disturb the gravel, but this is rare.

Pump is here:

Penguin 660R Powerhead

 

I'll give the gravel a good cleaning this week.

Kinda fond of my weed, it will be much less imposing in the new tank, RSN.

 

LOL, most polite Thread-Jack ever.

I moved the gang valve more to the Ludwigia pump output and dropped the PH to 6.7. Things might be a little perkier already, too soon too tell.