Some veg questions/possible nute problems

Hey guys, just finishing up the 4th week from seed on my first plant from seed. I just added an extra CFL 2 days ago and was considering upgrading to T5's. Temperature is mostly around 70F all the time, maybe 60-65 sometimes? Got a few little problems if you guys wouldn't mind helpin out.

I was replacing the water this week and noticed that the bucket was pretty dirty because a few hydroton rocks fell in there last week. I think it may have fucked with the pH, but it was around 6.0, I use the testing strips. Maybe it just locked out some nutes, but some of the old growth is def affected and the new growth has some funky stuff goin on. I'm not sure maybe I should just use plain water for this week, but I'm also concerned about the slow growth.. any ideas?

For T5s, how many would you guys recommend for vegging 1 plant to 12in?
My plan is to take a clone once this seed has reached 12in and then place her into my 12/12 room. I want to leave the clone inside the veg chamber for about 2-3 weeks and just keep repeating that process. I have a seedling mat and a heating pad for it as well. The only problem would be a dome because the dome is like 2in tall.. maybe I could use a tuppaware container?

I was wondering when to top or possibly fimm her. I've heard some people wait until 1 week into flowering and others start as soon as there are 3 nodes.. I have 4 nodes and the 5th one is just starting.

I really want to trim about 2/3 of the plant once I put her into flowering though. My last grow I ended up with a lot of tiny little buds that weren't mature at all. I had a 400w HPS goin, but the plants were too big I guess. I would just rather skip that step and start trimming the bottom part of the plant when I put her into flowering... is that a smart way to go?

Any kind of tip/suggestion/comment/anything is really helpful!
Peace!

I would think about flushing for a week then start on half strength nutrients. Which do you use? I use General hydroponics because they buffer the water to 6-6.5 which is where i always keep my plants. If you dont rinse the rocks well it can dirty the water but it never caused problems with me.

do you have a ppm meter?

JP

yeah looks like a ph issue try and get it 5.7-5.9 also go half strength on the nutes 5mL/1 gallon

I don't have a PPM meter yet, I'm about to upgrade a lot of stuff and will def get that for sure. I've been feeding them 1/4 str of General Hydro's MaxiGrow powder series. I'm pretty sure I've only fed her twice- 2 first weeks of plain water, then 2 weeks of 1/4str.