[edmundho]

HC Cuba & S. Repens yellowing

Need some help to figure out what's wrong.

First, some info:
20g Long, been planted for 1.5 months
Substrate: Netles Lambo from AI, with Seachem flourish tabs
Ei Dosing -- KNO3, KH2PO4 & TE from HydroTech [last test results: Ammonia 0ppm, Nitrite 0ppm, Nitrate 20ppm, PH 6.2, Phosphate 1.0ppm, KH 3.5, GH 8, weekly WC]
Filter -- Fluval 206 + Marina HOB s10 (for surface agitation)
Pressurized CO2 with upaqua inline atomizer -- indicator greenish yellow
Lighting -- Aquaticlife 2xT5HO, 24" above substrate. Lights on from 3pm to 11:30pm. CO2 on from 2pm to 11pm.

For the last 2 weeks, I notice my HC cuba (thanks walleye!) and my S. repens (thanks coldmantis!) are starting to yellow. I thought it was some kind of Fert Deficiencies at first, but the test results proved otherwise. Other plants in the tank are doing well. Pearling begins 2-3hrs after lights on (even the HC cuba ad S. repens)! But they are just not green and healthy looking like some of what our other members have.

Am I missing something here? Any help is much appreciated!

 

[edmundho]

Sorry, forgot to mention. The lamp is 2x24w T5HO from Sunblaster (6400K).

 

[jimmyjam]

check your nitrates again, hc is a huge nitrate sucker, def keep those up, and check your iron, it looks like a iron deficiency.

 

[pyrrolin]

I am seeing a yellowish shade all over. I notice you have lots of driftwood, maybe its tannins making everything look yellow. A large wc may help.

 

[edmundho]

Thanks jimmyjam and pyrrolin. I will do a check on nitrate and iron before my weekly 50% wc. I also lowered my light to 20" above substrate, crank up the co2, they seemed to yield some improvements on both plants.

Sent from my Nexus 4 using Tapatalk

 

[kyle]

I have noticed this on some of my tanks in the past and appeared to be the way the light fixture was set up.

Possibly if placed in center of the tank the edges of the bottom of the tank like the front dont get as much light depending on reflector and focus.

My solution was do play around with the light fixture by moving it forward. Your fixture appears to be high 24 inch from substrate you may want to try lowering it etc...

I also like JimmyJam response possible Iron/ nitrate deficiency

Also are you adding dry ferts? I havnt seen this mentioned before but I have always been curious...if the dry ferts are added to the aquarium and sit on the plants is it possible they are burning the plants?

 

[jimmyjam]

good call kyle, always check your lights, if your not getting enough lighting/ par at the bottom, this can def happen. If your doing ei dry fert, then make sure your dissolving it in luke warm water as described by tom barr.

 

[edmundho]

Thanks kyle. Yes, I was dosing dry and I also suspected those were burnt. Is it okay to mix the dry NPK together in water, right before dosing?

 

[coldmantis]

I know your dosing E.I are your following it exactly with the dosing amounts? I used to dose dry all the time I never noticed any yellowing. My 24" double t5ho is about 2 inches from the top trim of my 20g long and no yellowing.

 

[edmundho]

Thanks coldmantis. Yes, my dosing was quite exact. 2in above a 20 long is roughly 14 in above substrate? I think that's the trick. Mine was 24in above, and I just lowered it to 20in.

Sent from my Nexus 4 using Tapatalk

 

[jimmyjam]

you can dose all macros together, no problem, I have been making and selling my own mix for 5 years now, no problems mixed. I would suggest adding the iron if all those are not the issue.

 

[edmundho]

Thanks Jimmy. Will do, wait and see!

Sent from my Nexus 4 using Tapatalk

 

[jimmyjam]

http://www.aquaticplantcentral.com/forumapc/aquarium-pictures/showimage.php?i=7678&c=12

Here's a pic of S. Repens with iron deficiency. Look familiar?

Sent from my iPad using Tapatalk

 

[edmundho]

Thanks again Jimmy and everyone for your wonderful suggestions!

Here are a few updates:

• I have lowered the top light to around 20" above substrate. This is the lowest I think I should do without creating an algae breakout on my other plants.
• To give my S. repens and HC Cuba extra light, I have added another clip-on CFL, positioned 7" in front of the front glass between 7pm-9:30pm.
• All dosing amount remain virtually unchanged.

Now here are the results. I guess so far so good, uh?!

 

[jimmyjam]

thats a huge change, that took just 2 days? lighting deficit would typically take at least a week. Did you up your co2 as you upped your light as well?

 

[edmundho]

That's was about a week and a half. Mind you, the magic of camera white balance also helps too! Yes, the first thing I did was up the light and the CO2.