Cycling query

[Night]

Hi Guys and Gals,

90ltr tank (approx 82ltr water)
1 x HOB 600l/h with sponge,filter wool and alfagrog
1 x internal filter 300l/h sponge crushed coral
gravel and ornaments

Temp 30 degree C since start, just lowered to 28c to see if any different

Water out the tap: 7.5pH, KH 3dkh GH about 8/9

I REALLY need some advice please! I am currently 51 days into my fishless cycle and still no end in sight, but have had some hiccups along the way..I had a pH crash after 7 days (from 7.5 out the tap to 6 ish) sorted that out with bicarb, cycle progressed adding 3ppm ammonia every 2/3 days when it reduced to under 1ppm, nitrites were showing up and so was nitrates

3 weeks in and i thought i was done, it cleared 3ppm in 24 hrs, but as a precaution i added another dose @3ppm, 24 hrs later i had not cleared amm or nitrite (both were very low though), advice on another forum suggested test for nitrates which i did (off the charts) so i was advised to change most of the water, which i did, but i forgot to add the bicarb!!!! 24 hrs later i ran the tests again....amm still at 3ppm, nitrite high, but my pH had dropped through the floor again (very yellow on API)!!! I added some more bicarb to fetch it back up and i also added approx 40gr of crushed coral to the filter at this point just as a safety net.

I then added amm at 1ppm, just to try and get it back on track, but it was taking between 2/3 days to process, once i had to successive 0ppm amm results i added 3ppm, but again this is taking at least 2 days to process, i added 3ppm ammonia yesterday...test results tonight:
Amm 3ppm
Nitrite 0.50ish ppm
Nitrate off the chart
pH 7.5

I am a bit wary of doing water changes because of the 2 Ph crashes, peeps on the other forum are out of ideas, LFS said i should just wait until amm and nitrite reduce to 0, not add anymore ammonia and change the water slowly over a 3 week period!!?? as i am cycled? really at a loss what to do and seriously sick of looking at an fishless tank!! (and the wife/kids asking when we are getting fish lol) Any ideas would be appreciated!

 

[Delapool]

Hi, welcome to the forum. Hope I can catch some of your questions.

I'm not aware of bicarb causing any issues with cycling. IMO your cycle is there but it seems to run out of steam(?) and the ph crashing suggests the kh is being chewed through rapidly (at those high temps). The lack of kh and low ph reduce bacterial activity. Both of these happen naturally so I would favor some tweaks to the tank.

I would add a bag with a handful of crushed coral under your filter outlet. The ph crash is just an issue now - with fish in it could stress them so I would favor preventing these.

Do a large water change to get nitrates back to readable again.

Crushed coral can be slow to react so I would also suggest testing ph in morning and night - as soon as it starts to drop, then add some bicarb. You will need to dial this in.

 

[Night]

Thanks Delapool, i think that my tank is now cycled!! i have had 2 0ppm ammonia and nitrite results after adding 3ppm ammonia, but now i am concerned with the water change as i have done a 90/100% change prior and it crashed the pH, so i was wondering.....to get the nitrates down could i do a 30% change, leave it 24hrs do another and continue this way to reduce them? also if i have to add bicarb...is that safe for the fish? (i have not got any yet...just don't wasnt to add them if it is an issue with the bicarb)

I added about 40 grams of crushed coral to the filter about 2/3 weeks ago i hopes of stabilizing it, and so far my pH has been a constant 7.5, but i don't know if that is the coral or the bicarb???

 

[Delapool]

Just checking but water is 7.5 ph and 3 kh straight out of the tap?

Could you leave a jar of tap water to degas for 24hrs and then retest if not already done? This will give a truer value of tap ph.

Bicarb is safe for the fish.

 

[Night]

Yeah I have already done that and it stays the same, I caught the 1st crash 1 week into it, the 2nd was after a big water change so I can only think that it was the nitrifying process? I am presuming it is 7.5, API normal pH shows 7.6, high pH shows as 7.4

The only way I can test kh and gh is with test strips, which show 3kh and 8gh, I know that strips are unreliable at best, but it does match pretty close with water boards website.

 

[Delapool]

Yeah I have already done that and it stays the same, I caught the 1st crash 1 week into it, the 2nd was after a big water change so I can only think that it was the nitrifying process? I am presuming it is 7.5, API normal pH shows 7.6, high pH shows as 7.4



The only way I can test kh and gh is with test strips, which show 3kh and 8gh, I know that strips are unreliable at best, but it does match pretty close with water boards website.

Yes, it must be the bacteria unless you have lots of new driftwood or are using ph buffers (apart from the bicarb / coral).

Imo I would grab something like the api kh (and probably gh as well) liquid test for the accuracy as I think this will be ongoing management.

Did you test kh in tank before the large water change? Just curious on what kh you need to hold tank ph.

With the tank cycled you could also lower temp down to say 25C (or whatever suits the fish you are looking at getting). This will slow down the bacterial activity.

 

[Night]

ok, so i have done the big water change now my cycle has completed, pH has stayed stable at 7.2ish (had to tell with all the colours almost the same!!) for 24hrs, just need to get to the fish shop tomorrow then i don't need to add anymore ammonia!!

Delapool. i have just measured the kh/gh (with teststrips ) and they read at:
KH 3
GH 8

I'm not sure if the coral i have added is acutually having any effect, but i have left it in as it is not raising the pH, and everything seems to be OK, i will keep checking the pH regularly just to be safe

Thanks for your help, once again

 

[Night]

I stand corrected....just tested pH and it's dropped to 6.6, no idea why, i have no wood in it,just plastic plants, but this did happen last time, very confusing, anyway at least i did not get any fish today! i will add small amounts of bicarb to try and fetch it back up to tap water levels and i guess i will have to look at maybe adding more coral or do more smaller water changes when i have fish?