Cycle Crashing

[jackthelad]

Hi, everyone im new to tis forum but i have been on another forum since i started my cycle almost three months ago my tank has been cycled now for about seven weeks but i havnt added fish yet as i have just moved house and didnt want to put the fish through the stress of moving as the tap water in the new house is totally different to my old house.Since the move my tank ph has crashed from ph 8.0 to 6.0 in the first week and my kh seems to be dropping rather quickly i did almost full water change last week to get it back to normal but i have been testing the ph and kh everyday since then this morning the ph was 7.8 and the kh was 0

my tank holds 70l fluval 2 plus filter and a rena smart heater
sand substrate plastic plants small piece of bogwood and a few ornaments


tap water stats for my old house is as follows
ph 7.8
nitrate 20-40mg/l
gh 12
kh 9

tap water from my new house
ph 8.0
nitrate omg/l
gh 8
kh 6

tank water stats today
ph 7.8
nitrite processing in less than twelve hours
ammonia processing in less than twelve hours
nitrate 80mg/l
kh 0
gh7

I WOULD BE GRATEFUL FOR SOME HELP HERE AS I FEEL LIKE PACKING THE WHOLE THING IN

 

[Miss Wiggle]

the process of nitrification itself (i.e. cycling) causes pH to crash, if yours keeps dropping it will stall the cycle. it's fairly simply rectified in a cycling tank, add some baking soda, this will buffer up the kH and consequently keep the pH steady and then the cycle should go smoothly.

have a read of the link in my sig on pH which gives more details and instructions for quantities of baking soda to add etc.

 

[rabbut]

OK, KH nutralises any acidic substances. Nitrate is acidic, and thus "uses up" the KH to keep the pH stable, and so with nitrate running high, as it does at the end of a fishless cycle, the KH gets used up making the pH prone to crashing, as without KH, there is nothing to stop the acidic nitrate pulling the pH down. What you are experiencing is normal, don't worry about the issue too much. Your KH is fine for fish (in fact better for most common community fish) at the new house, but it just isn't great for fishless cycling. This can be remadied by adding baking soda to raise the KH untill you do the large waterchange in readyness for fish This is a fix that should only be used while cycling, don't use baking soda once you get your fish The alternative is to do a few waterchanges to add some hardness from the tap also

The pH with fish in the tank should remain stable, but if it doesn't, you can add cruched coral grael (about 1/2 a palm full only) to keep the KH up The crushed gravel is the long-term fix, but is expencive if you are just using it for fishless cycling, hence why I advise using baking soda The coral gravel works by slowly disolving into the water

All the best
Rabbut

 

[jackthelad]

Thanks guys thats a load of my mind will defo read through your sigs. I will keep you up to date with whats happening

 

[jackthelad]

ok an update with my tank.i added some baking soda to the tank yesterday and every thing is sitting pretty at the moment.
So im off work for a couple of days and hope to go and get fish.Would be grateful for some ideas on what fish to get the kind of food they eat.I would like to start with some zebra danios and some blackskirt tetras or purple emperor tetras but not sure about these going to gether

 

[Miss Wiggle]

ok an update with my tank.i added some baking soda to the tank yesterday and every thing is sitting pretty at the moment.
So im off work for a couple of days and hope to go and get fish.Would be grateful for some ideas on what fish to get the kind of food they eat.I would like to start with some zebra danios and some blackskirt tetras or purple emperor tetras but not sure about these going to gether

glad it's settled down

some danio's would be a good choice as they're nice and hardy

in a 70l tank you'd probably be best sticking with the smaller tetras that stay around 1", the blackskirts or emporers would work but the tank is on the small side for them.

i'd look at a group of cories as well and also something like a pair of rams or a trio of apistos as feature fish

 

[jackthelad]

Could you recommend what kind of apisto would suit my tank water as my ph is rather high at 7.9 usually.would bolivian rams be ok or what about cherry barbs