More Q's (sorry): floating plants, nitrogen during cycling

[QandD 573]

Hi, sorry for all of the questions lately. I am planning to start dosing potassium before I take the plunge and go the dry fert route, but I also ordered Seachem Nitrogen since I am noticing some yellowing on new growth (namely my sword). However, I'm still cycling the tank (high nitrite phase), and I don't want to screw anything up. Would it be advisable to hold off on any kind of Nitrogen dosage until things settle and the fish can fertilize everything? Nitrates are at around 5 ppm before I do a big water change. 

 

One other question: my Brazilian pennywort keeps wanting just to float in the tank. Should I let it? I've noticed that some people seem to be able to grow the pennywort in kind of an attractive daisy chain, but my penny wort just wants to float all over, which I don't find attractive. Would I have to put the stems close together (floating one of them) with the hope that their aerial roots will link them?  Or should I just keep replanting them? I've also noticed that my creeping Charlie wants to be more of a thicket than a set of orderly planted stems, so I've let a couple float in the thicket there.

 

Would it need more water column ferts to succeed? (I use Excel and Flourish comprehensive... and the potassium soon). My pennywort isn't growing as much as I'd anticipated and isn't sending out a lot of aerial roots. The Charlie is doing better. By contrast, my bulb plants are doing decently (growing some new leaves fairly regularly.

 

Sorry for all of the questions again and thanks for any advice. 

[shakaho 6,312]

Aquatic plants prefer ammonia as a nitrogen source.  They will use nitrate if no ammonia is available.  I would not add nitrogen fertilizer to  a fish tank (current or future).  Since you have nitrate in the tank water, your plants have all the nitrogen they can use.  Many nutritional deficiencies cause yellowing. 

[QandD 573]

OK--thanks. Once I get the nitrogen I'll send it back to Amazon! 

[Daniel 5,668]

About the pennywort, it will grow either way. Let it float if you want or keep replanting until it roots. If you have a decent clump, what you can do is wrap the plant around a small rock and place it on the substrate. It will take root eventually.