Not sure what the problem is?

[stujo]

I have a 200l well planted tank which has (or had) had been running pretty well for a year or so now. Substrate is Akadama with JBL Aquabasis Plus below. Pressurised CO2 and EI dosing. Filtration 10x (rated) plus 2 Koralis. Lighting is about 1.8 wpg. Filters cleaned regularly, substrate vacuumed weekly etc. along with 50% water change

The problems seem to have started following a quite large rescape which disturbed the JBL Aquabasis somewhat and I got a lot of rhizo. I did 50-80% water changes twice a week for a few weeks and also did a 4 day blackout. The rhizo seems to have almost gone but I now seem to have more serious problems. Even with weekly vacuuming I have what I can only describe as a brown dust/layer growing/appearing on top of the substrate and also the substrate I can see at the front seems to be going black below surface level. My water is also not crystal clear as it normally is and there is a slight brown "dust like" covering on the water surface, not really scum, more dust like.

This has all happened very rapidly, not gradually and even with meticulous and regular cleaning is gradually getting worse. Fish don't seem to be affected , my amanos are fine also. My plants show new "clean" growth at top, but below that seem to be very much covered in what looks like brown algae, but not convinced it is in fact brown algae.

Not sure what to try now, perhaps will need to completely strip down and start again?? - Any ideas please? Not sure how to post a photo but have tried? The first photo shows the black below substrate and the second pic shows the brown "stuff" spreading rapidly on top of substrate. I know it looks a complete mess and it annoys me so much, its normally spotlessly clean with plants growing well!! In fact I've been removing and throwing away the more delicate plants as I cant keep them clean. http://imageshack.us/f/88/p1000178po.jpg/
http://imageshack.us/photo/my-images/600/p1000179m.jpg/

 

[wearsbunnyslippers]

sounds like you might have stirred up some silicates which has started off diatoms again. and you may have also given yourself a bacteria bloom.

do you use dechlor when you change your water?

not much you can do about a bacteria bloom except wait it out or get a uv sterilizer. as you have already seen the large water changes dont help, they just mask it for a while.

get some otto's to clear the diatoms, this is some of their favourite food, once they have done there job, you will need to feed them veggies though, like baby marrow, spinach etc. they will also go away on their own once they have removed all the free silicates..

the oily film/ scum on the top is also related to bacteria and diatoms, and will clear up with the uv or go away on its own. syphoning it off with water changes, or adding a tiny bit of surface agitation to try and get it into the water column so it can be sucked into the filter also works. if this still plagues you, look at getting or diy'ing a surface skimmer like this:

when you are rescaping in future, unless you are moving crypts or swords or other heavy root feeders, don't uproot the plants, just trim them off level with the substrate, and replant the tops where you want them, this prevents the substrate from being disturbed, and the roots that are left behind break down in a few days, adding their nutrients back to the substrate as well.

 

[stujo]

Hi - thanks for your reply and this makes sense. Yes I do use dechlorinator when changing water. I was in fact splitting a big area of crypts as they were outgrowing themselves, hence the rather large substrate disturbance. I have got ottos, originally had six, but can can only find three, so will buy more of these, when the tank is v.clean I feed them with veggie pellets, spinach etc. I should have added that my plants are in fact still growing well and in fact pearling each evening, just covered in "gunge" apart from the tops. In fact have to admit I wasn't aware of UV's for aquariums, have recently built a quite large (2000g) pond but had left it sitting full of water and nothing in it for a while and had green water. I was amazed how quickly the UV gave me cristal clear water, in fact it made it so clear I could see the pumps etc on the bottom (and its over a metre deep), so have now switched it off for a while.

Anyway many thanks for input, I'll keep at it.