Tank cleaning during the cycle?

[Zoomy]

Hey guys, question for you:

So my planted 18 gallon has been cycling for almost three weeks now and isn't done, though that's not my current concern. Rather, there's a good amount of hair algae and diatoms covering everything, and I feel like I am literally watching my plants die.

Is it ok to do a water change and suck up some of this algae while the tank is CYCLING, or is that going to do more harm than anything? I think I already caused my cycle to have to play 'catch-up' when I topped off the water last week and it was a bit too cold, and now I'm just fretting.

....Because, really, I would prefer to not kill my plants.

Suggestions, expertise, advise?

 

[20cc]

if you have diatoms you are most probably done cycling

 

[Mebbid]

How exactly are you doing the cycle? Is this fish in or fishless? What's your ammonia source?

A water change won't ever harm the bacteria in a tank as long as it's dechlorinated first.

Now for some plant related questions:
What lights are you using?
How long are you leaving the lights on?
What plants do you have?
What is your source of fertilizer if any?
What is your carbon source if any?

 

[Zoomy]

I wish I was done cycling :C, but nitrites are still off the charts (the solution turns purple as soon as it hits the bottom, though it isn't staying purple as long so maybe that number is finally going down), and my ammonia was going from around 4 to 0ppm for a couple days, but hasn't been going down past .5ppm the past few days. Ughhh.

And right, that information would probably be important:

FIshless cycle
Pure ammonia, the ACE Hardware brand
Lights: two CFL daylight bulbs, 1170 lumens each, comparable to 75W incandescent (but CFLs use less). It's not high light, which is fine, they get the job done well enough.

Lights are on no more than 6 hours., from 11am to 5pm.

Current plants IN the tank are: Brazillian pennywort, golden creeping jenny, and Hygrophilia angustifolia. I just received from creeping charlie, java fern, Rotala rotundifolia indicia, and Rotala nanjenshan yesterday though, which will be put in soon. ( I realize the indicia may not stay red under my lighting, but that's fine). The creeping jenny is what I'm currently worried about, as I can see roots and leaves starting to die as too many diatoms accumulate on them. But the same thing is happening to a couple hygrophilia leaves, which really saddens me.

Fertilizers: I'm just using Seachem Flourish comprehensive a couple times a week, and CO2 wise, it's just Flourish liquid CO2 every day.

The plants ARE growing and have been since day one, the worry is that the diatoms and hair algae are spreading to the plant's leaves and stems and looking like it's killing them.

 

[Rivercats]

You can only use 1 light for now and also raise your dosing level of liquid carbon to 1ml per every 5 gallons of water. I've also never dosed ferts during cycling but that is just me. If you cut your lighting down to one bulb and raise your liquid carbon dose it will greatly help keep diatom and hair algae growth down. But I would also spot treat the hair algae with hydrogen peroxide 3%. A picture of the algae would be good to verify it is indeed hair algae. But back to spot treating.... turn off your filters, pull up 3ml of peroxide to every 1 gallon of water into a syringe, slowly squirt the algae and leave the filters off for 20 minutes. If you have a lot of algae you can repeat this treatment daily until all the hair algae is treated.