My Roma 240 water

[angelah]

Hi all,
Maybe somebody can shed some light on this for me.

My 240L giving odd readings.
Tank was started on Friday 18th Feb. I used the JBL AquaBasicPlus to about 25mm and then JBL sand to 25-30 mm and planted up heavily.
Filtration is by a Fluval 305 with it's original carbon (initially) and ceramics and a JBL e 1500, both externals.
There are 3 pieces of bogwood, a few safe stones and that's about it. There was a mulm exchange between my son's filter media but the filters cleared that brown muddy look in under 2 hours. The tank was then started on a fishless cycle to 4 ppm using Boots ammonia.
By the 20th readings were ammonia 6 ppm and nitrites 0. I was away at a military fair all that weekend and arrived back home late on Sunday 28th when I quickly took tests. Ammonia was zero (!) and nitrite 0.6. It was clearly obvious the plants had grown quite a lot.
Readings on 1st March; ammonia 0 and nitrite 0.6 still. Tested pH which was 7.2.
2nd March readings stayed the same as they also did on the 3rd. Nitrates tested at 90 ppm.
On 4th ammonia came in at 1.0 but nitrites stayed at 0.
5th showed ammonia at 1.5 ppm (dosing all the time to 4 ppm) and nitrites still 0.
By the evening of the 6th ammonia showed at 1.0 again and nitrites 2.0. Nitrates had gone off the API chart scale. GH was 80 and KH 20 ppm.
On the 8th ammonia was still at 1.0, nitrites 0, nitrates still off the scale but the pH had dropped to 6.0. I used some bicarb to raise the pH to 7.0.
Today ammonia is 0.0, nitrites 2.0, pH back to 6.6, KH was maybe just about nudging 30 ppm.

Ammonia was calculated for the correct amount to return it to 4 ppm on every reading at between 12 and 24 hours. Plants have shot up, Cabomba has grown about a foot or more.

Has anybody any idea what's going on please? I am completed mystified. Nor can I seem to get a steady cycle running - or maybe it's run?

Won't be testing levels again until 2000 hours.

Angela

 

[Tom]

If I were you I would stop dosing the ammonia, wait for the NH3 and NO2 readings to hit 0, do a 50% water change and start stocking the tank. If you add a few small fish at a time (say 10-20 tetras) into a 240 liter, it will have very little impact on the biofiltration and you can build it up from there. Then drop any reliance on test kits that are probably inaccurate (particularly NH3) and watch the fish.

What you're doing now, in my opinion, is way overkill. You are seeing NH3, NO2 and NO3, so you have the necessary bacteria present. If you just wait without dosing until the filter has turned it all to NO3 then do a good water change and you're ready to stock. The longer you continue to add NH3, the longer your cycle will go on for. I doubt your fish will produce 4ppm NH3 daily, so you would just starve the bacteria you spent so long building up.

Or am I misunderstanding your aims?

Tom

 

[ceg4048]

Hi,
My preferred approach is to stop adding ammonia to the tank and to stop testing. Firstly, the test kits are not accurate so it's not surprising at all that they produce mystifying numbers. Secondly, a planted tank does not need to have these levels of ammonia added to the tank, but if ammonia is added then the plants will consume as much as they can depending on the amount of CO2 available to them. Any nitrate that is formed from bacterial action will also be consumed.

What many people who add ammonia don't realize is that high concentrations of ammonia is toxic to the very same bacteria that we are trying to grow. Additionally, nitrifying bacteria also require a lot more things than just ammonia to quickly build their populations. They require Phosphate, Potassium, CO2, carbohydrates, Magnesium, Oxygen and other compounds. The very same things that we feed our plants and the very same byproducts of plant metabolism are used by the bacteria. So that one creates a dizzying combination of ammonia pull-down from plant consumption as well as from bacterial population crash and re-build after the ammonia levels drop below toxicity levels.

The more the plants grow the stronger the effect they have on ammonia pull-down. This is why fishless cycling on a planted tank is irrelevant. Ammonia input by fish and food waste is absorbed by the plants so you are not going to see the nice steady nitrogen profiles that you might otherwise see in an unplanted tank.

Cheers,

 

[angelah]

Okay, and thanks for helping. I think it's settling down now anyway, it may have been caused by Welsh Water when they changed water source, it seems it happens here.

Angela