Came home from holiday to find fish breathing at the surface, water smells terrible (even though just a week without WC ) and everything overgrown.

I figured, too much food WC should fix it all up. ... ... Nope.

I did 1 big one that night asap. The fish seemed fine for a few minutes but before half an hour was up they were back at the surface. I left it for the night and in the morning did another large wc. Same thing happened except they don't seem to spend all their time up there...

Glass was very dirty but I didn't clean it until this morning and I see what looks to be like cyanobacteria on the sand.

Except it is white.

Should I treat for cyano or am I dealing with something different.

Light had been left on for the week as well... :facepalm: :evil:

Hi Dennis. It sounds like a lack of oxygen. Maybe all the extra light caused an algae bloom and it's stripping the oxygen from the water??

Whatever the cause I suggest you get some extra surface movement, either by having the inlet just above the water level to break the surface or by adding an airstone which will achieve the same thing.

Definite lack of oxygen. Have added surface movement and removed a lot of the duckweed which was on top. (Probably prevented an algae bloom).

This isn't algae I'm pretty sure. It's white. Almost like a cobweb. I would expect algae to be green from chlorophyll.

I know cyanobacteria can cause these symptoms but I'm not sure if it is this because it is white. Which kinda contradicts the "cyan" in "cyanobacteria"...

It can also be red.

If you have been away, were the rest of the family members? Was the house shut up? That, combined with the lights being left on will be the culprit.

I should think the water chnages plus added oxygen will see them coming right (hopefully) over the next day or two.

Others have mentioned that white cobwebby algae before. Remove it by hand, or siphon it up, and see if it returns once conditions are back to normal.

DIY Co2?

House was closed, someone novice came to feed all pets so not much can be expected.

Have removed most of the white cobweb stuff and increased surface movement. Fish seem to be back to normal now.

No DIY co2.

Hopefully all goes well. Thanks.

ammonia?

Thats what I thought at first, but after 2 big WCs, probably over 100% they were still doing it...

did you wipe the glass while a water change?

No.

Its not sediment of any sort I'm pretty sure.

It was almost exactly like cyano.

fish may have been overfed and the white stuff was mould that had grown on the excess food on the substrate

did you do a gravel vac as well as water change as the gravel under the white stuff may have become anaerobic

just a thought

We get white fluffy mould when Miss Nine overfeeds her tank :evil:

Can't gravel vac cos its sand.

Its not the same as the over feed mould. I'll grab a pic if it comes back, or if I see more.

New wood?

New wood?

Two of the new bits of wood that I have placed in my newly setup (using old filter media) tank have white gray 'algae' that has developed in the last few days. Both bits are well aged and native timber - very hard and dense, both sunk with no problems even though one had been dry for at least 12 years.

I'll try and get a pic later, the same stuff?

New wood?

viewtopic.php?f=4&t=48302&hilit=smoking

Is it anything like that Dennis?

Nope. Not at all.

It is not smokey, it is not sediment and it is not fungus on left-overs. It is almost exactly like cyanobacteria.

Very white, carpet like stuff on patches of sand and wood.

You really need to post a photo so that all the guessing games can stop

Yeah. I will.

If it comes back (Which I think it might) I will.

I don't have a decent camera on me but IDK.

Will update if I find any.

We get white fluffy mould when Miss Nine overfeeds her tank :evil:

yep and I reckon thats exactly what it is - overfeeding and the leftover food is the white gunk.

I've had it happen and it looks like sheet covering the bottom of the tank.