Bacterial Bloom

A pint of untreated tap water added to you tank 12 to 24 hours later and it
should be gone done it loads of times the concentration are to low to harm
the fish but sort the bloom out bigger the tank the larger the amount to use

However you decide to deal with it, I would maximise aeration in the meantime as bacterial blooms can reduce oxygen levels. Probably won't be an issue with a lightly stocked tank, and in particular with a Betta owing to them having a labyrinth organ, but still wouldn't hurt.

pint of untreated is an easy cure

Fc76 this is what happend to my tank but I had fish deaths too, does it have a smell to it fc76?

Yeah it did have that smell 
Not sure what that is then?? I know the feeling though although my cycle finished Im waiting till pay day to get fish but my filter has developed a strange knocking sound, no matter what I do it doesn't quite seem to go away, if it's not one thing it's another eh! 

Untreated water in small amounts up to 10% is OK in mature tanks but not immature ones. Mature is defined as a tank that had been running for at least 6 months. It takes that long for the biofilm to develop fully. The ammonia and nitrite eating bacteria live within the biofilm, and until it is fully developed the film can't protect the bacteria.
That's why I don't advise adding untreated water to new tanks, too risky.

But at least yours did sort itself out in the end, Mad_BMS.

Hi Biff,

PH is a steady 7.

 

Today the bloom had started to go - YAY!!!! 

But.... 

Stanley has fungus growing on his fins and the start of an ulcer just in front of his dorsal fin so I took the decision to treat him with Esha 2000 anyway. I took the lid off his tank and was hit by the stench of rotten eggs!! 

So. Out came the snails. They have moved to the QT (I'm never sure if the T represents the Tine of quarantine or tank?!?! ) and Stan's tank was syphoned and refilled, water treated, esha 2000 added, blah, blah,blah.....

The snails are loving it in their new warm (28*C - to speed along the nitrogen cycle) tank and i've posted a photo of my Sulawesi snail as it is the first time since i got him that he has a) moved very much and b) not climbed straight out of the water!!!!  He is gorgeous!!!!

I have popped some spinach and some blood worm in there for them and the filter was run in my 54 litre tank for two weeks then soaked in filter sponge squeezings too and I added 10ml of Quick Start for good measure!!!!

I did wonder though, and seeing your comment about lime scale Biff am still wondering if the rocks i have in Stans tank are causing a problem with the water.  I collected them on the beach in Whitstable a couple of years ago. Then they lived on the rockery in the garden for a year then they were boiled and soaked in salty water, then rinsed in tap water before going into Stans tank. They have now started to go black, having started out being a sandy colour.  I don't know what the rocks off the kentish coast are but could they be significant to the bloom???

Anyway, here is the photo of my snail.

FC76
 

Oh, by the way Biff I have internal filters in all my tanks with sponge media.

According to my records, the bloom occured 13 days after the rocks went into the tank. Today the tank is clear but then it was cleaned thoroughly yesterday. Plants are all live and all fine, apart from the Hygrophila Polysperma Pink that has died in both tanks, so I don't think it's related.

I'll keep an eye on things and report back if anything interesting happens!!!

Speaking of interesting things, I watched my fish eating a dead nerite snail this evening. My corys were desperately trying to turn his shell over. I suspected he had died so I lifted him out of the tank and sniffed him and sure enough, dead snail!!!  I prised his trap door off and popped him back in the tank and suddenly all my fish turned into piranhas!!!! I've never seen anything like it!!! They pulled his remains out of the shell and devoured him. My biggest Glowlight (known as big mama) was swimming round with a massive bit of snail hanging out of her mouth!!! I know it's a bit grim but at least I didn't have to feed them!!!! 

Anyway, I have four year old with me who is refusing to go to sleep so I'm off!!!

FC76

The blackness on the bottom of the rocks is caused by the action of anaerobic bacteria, as is the smell. Substrate under rocks can easily become anaerobic as there is no water circulation under them, particularly if the substrate is deep and/or compacted, or if waste matter is collecting under the rocks. Better leave the rocks out for now, it has nothing to do with the type of rock.