Ok, I have a 60 litre tank that I'm trying to cycle. It was on the way, with nitrates being produced, when it crashed and we are, apparently, back at square one. The specifics are:
60 litres, with led lighting (Juwel Primo tank)
Eco Complete substrate 1/2 and Unipac sand 1/2
one large piece of bogwood
Planted with two java ferns (on wood), and approximately 10 other plants, including an area of a grassy-looking plant in the substrate that I can't remember the name of. And two mossballs.
Juwel Bioflow One filter (for 80 litre tank)
Prime to condition the water.
The tank lights are on from 9 to noon, and then from 5pm to 9pm.
The temp is about 25c (maybe a bit over).
I also have a little 5 gallon tank, rounded gravel, with a Tetra Whisper and an Eheim filter running. It's stocked and has been up for two years.
Tap water has no nitrates or nitrites, and is very soft. Its parameters (from the Scottish Water) are German 0.94. the CaCo3 is 16.85. When I initially tested it I was getting between 6.0 and 6.5 on the PH using the API dipsticks. After being in the tank it has dropped to 6.0 (possibly lower, but that was the bottom of the scale).
I had to put a double-dose of API "Up" (sodium carbonate) in to make any noticeable difference in the Ph level.
I am now using the API master test kit and it's a very pale 6.0 Ph (without any "Up" added).
I have put a little packet of what is supposed to be dolomite gravel in each tank, where the water will run over it coming out of the filters.
To aid the cycling, I pulled a small over-the-back filter that I'd had on a five gallon aquarium that has been up and running for two years and put it on this one. I later sacrificed the filter media to this tank. (I had another filter running on the five gallon and had for two months, so it should have kept everyone alive until the other filter was back. The five gallon was overstocked due to unexpected offspring.)
I had been cycling the 60 litre fish-less since early May, had a nitrite spike that was coming down, and had 20 ppm of nitrates. Earlier this week, the nitrites disappeared, so I was happy until I saw the nitrates were also gone, and the ammonia was up again.
I did a 75% water change and planned to start over in another fish-less cycle try, except that the five gallon tank "crashed" badly at that point and I lost several baby albino corys. I moved six surviving very young albino corys over to the 60 litre tank, and have been monitoring it carefully. They've been getting a 25% to 33% water change every day to bring the ammonia down.
This morning it was, after 24 hours since the last change, between .5 and 1.0. I've just done another 33% water change and will be testing shortly to make sure it's ok. The five gallon tank is pretty much getting flushed every other day and having partial water changes every morning and evening. It contains three adult albino corys and four neons that I am trying to keep alive until the corys can be moved to the large tank. (After which the neons should have a better time of it in there.)
The plants are doing well in the large tank, except the mossballs. They seem to be getting just a bit brown and don't look good, and I'm not quite sure why. I am going to pull them out of the tank and put them elsewhere for a while to see if they perk back up. The mossball in the small tank looked very bad indeed and has been removed. The other live plant in there is doing well. All the other plants have pretty much doubled in size in three weeks, except the java ferns (that seem healthy) and the mossballs.
In a panic yesterday I added Dr. Tim's bacteria to each filter to try to help jump-start the cycle again. (Triple the dose, actually.) And will continue to add to it in the small tank as I am having to do such massive water changes so often.
I am using Prime, and I know that can give a positive reading for ammonia that is temporarily "safe" (24 to 48 hours?). Due to the size of the small tank, I've not got really many other options that I know about other than the constant water changes to keep the fish safe.
Do you have any advice for anything else I can be doing to help these tanks get cycling again? They have to have the fish in them, unfortunately. I'm afraid to move anyone else from the small tank to the large one, but as soon as I can I would like to move the adult corys over one a week. I'm kind of amazed that the six babies (they are about 1 to 2cm long) could raise the ammonia in a 60 litre tank overnight. Could the bogwood have anything to do with that? I have put a sinking wafer in for them, given them a half hour with it, and then removed the remains. Now I'm putting in 1/2 of a sinking wafer daily, and it's disappearing in the half hour. They are very avidly rooting around and up on the bogwood and plants, etc.
Should I use more "Up" to try to raise the Ph slightly in the water that is going into the tanks in a water change?
I am due to get some cockleshells to add to the tank today, assuming my vendor has them in (as he'd hoped).
Other than keeping changing the water, which I'm ok with as I'm retired and home all day, and testing for ammonia/nitrites is there anything else I can be doing at this point?
EDIT: Have just found this handy chart
http://www.ecofilms.com.au/aquaponics-health-understanding-ammonia-water-temperature-and-ph-balance/comment-page-1/#comment-676638 and am breathing a bit easier tonight.