Green Goddess's First Fishless Cycle (240 Ltr)

[greengoddess]

I did the water change last night. I've now discovered a distinct disadvantage of having a large tank... the water changes are donkey work!

It was going to take so long that I ended up turning off the pump, throwing in a load of dechlorinator and then filling the tank using a hosepipe. I finally got it filled and the temperature was 23 degrees celcius. Not exactly 29 degrees but better than the 10 degrees it would have been if I'd just used cold water. I then added bicarb to raise the pH to 7.5 - 8.0 and finally switched the pump and heater back on. I also added the required dose of ammonia to take it back to 3ppm.

I know this was a lazy way of refilling the tank and I hope I haven't done anything that will kill off the bacteria in the filter.

 

[waterdrop]

Don't worry, a period of cold is not going to bother the bacteria.

Water change time is one of the first things I think about when I think about tank sizes.

~~waterdrop~~

 

[greengoddess]

OK, that's good news. Many thanks again Waterdrop. I was worried that adding the water by hose would have had a negative effect on the bacteria because I added dechlorinator to the tank instead of adding it to the water first. I did switch off the filtration whilst I was filling it and only switched it back on once I had mixed in the dechlorinator. Hopefully it should be OK.

 

[greengoddess]

Good news, after 24 hours the ammonia reading was zero again so it looks like the bacteria are all still healthy. The nitrite has already gone back up to 3.3 and the nitrate was approx 90. I found that very surprising as I thought the 95% water change would have reduced the nitrate and nitrite drastically for a few days. I didn't realise that nitrite and nitrate could appear again so quickly after such a huge water change. Anyway, the main thing is that the cycle is still running along nicely. Temperature is also back up to 28 degrees and I also added three nice silk plants to the aquarium during the water change so now the tank is a little more interesting to look at.


Oh, one question about the carbon filter that I put in the filter at the start of the cycle. Is that still OK to leave in or should I take it out and throw it away yet?

 

[waterdrop]

I would not change out any part of a filter, even carbon, if I could help it during cycling. Don't forget that virtually all of the types of media we put in our filters have degrees of overlap in functions. Even though each one has a primary function that its the best at or is the reason we use it, it will often also perform one or more of the other functions that is not its primary purpose. So, even though carbon's primary purpose is as a "chemical" media, it will also harbor bacteria and perform a secondary function of biological filtration and it will also trap some debris, performing a mechnanical function. Another example of this would be filter floss. Its primary purpose is fine mechanical filtration (trapping very small debris particles) and yet, of course, bacteria will get in there to some extent too! Or sponges: they are among the best biomedia and yet they are quite good at mechanical filtration too but do virtually no chemical filtration.

So leave that carbon in there until you are 6 months out or so before you start the gradual process of replacing it. All media should be replaced in subset segments if possible, but if its a big filter and has plenty of other media of the same function then of course a "whole sponge" or "whole mesh bag" of something might be ok to change out if it were of a type not wanted in the future.

~~waterdrop~~

 

[greengoddess]

Thanks Waterdrop, the carbon will stay for a few months in that case. I'll replace it with a coarse sponge when I eventually remove it.

Strangely, today the ammonia level had not gone back to zero but had reduced down to about 1.5ppm. The nitrite was 3.3 and the nitrate was 90. I am assuming the bacteria are suffering from a slight shock after the water change, hence the presence of some leftover ammonia.

Annoyingly, I am off to the Netherlands first thing tomorrow morning for a couple of days. I had prepared two 3.2ml batches of ammonia for the wife to add while I'm away but now I'm not sure when to tell her to add it. She won't be testing the water while I'm away so I don't really know what to do.

My beginners instinct tells me to tell the wife to leave the tank alone tomorrow completely and ask her to add a single batch of ammonia on the following evening. The day after that I will be back home and can test the water properly again. I really hope this doesn't end in total disaster at this crucial stage.

I'm off to bed now to grab some sleep before I leave in the morning so there's no time for a back up plan now. I'll try and check this forum when I'm away and I can then telephone the wife with any special instructions if necessary.

 

[waterdrop]

The "every other day" type plan you outlined sounds fine. The time period is not really long enough for anything to get messed up. WD

 

[greengoddess]

Hi Waterdrop, I'm back home now. My wife added the ammonia on Sunday night. I tested the water today and the ammonia had dropped to zero thankfully. The nitrite is 3.0 but I think the nitrate might be starting to go off the scale again because the colour of the solution in the test tube looked a bit funny. The nitrate is either 70 or it's totally off the scale. I will have to check it again soon to keep an eye on it. pH is stable at around 7.0 - 7.5, the water is clear and the temperature is a steady 28 celcius.

 

[waterdrop]

Sounds like you made it through ok!

 

[greengoddess]

Tested again today and I think the nitrate must be off the scale again. If so, the effect of the 95% water change didn't last long. The ammonia is still being gobbled up nicely and the nitrite level is a steady 3.0. Is it worth messing about with another 95% water change or do you think I just just leave it alone and continue as normal?

 

[waterdrop]

How long has it been since that last water change? Its a great sign that the nitrogen is quickly making it all the way through the cycle to nitrate. Its certainly not a necessity, given how recently I think the last one was. But you can decide. If you have the time on a weekend, it should help, not hurt, to take the nitite/nitrate down.

~~waterdrop~~

 

[greengoddess]

Hi Waterdrop,

From the last water change to the point of the nitrates going off scale was around a week. Unfortunately I don't think I am going have the time to do a water change until the middle of next week... unless of course it is an emergency, in which case I would have to make time. As long as leaving the water as it is will not hurt the cycle then I am happy to leave it alone for a while.

 

[waterdrop]

You haven't listed pH in a long time, but I assume that's holding up as yours was always too high if anything. There's no way you need to worry that much about changing it. Wait until you have more time. WD

 

[greengoddess]

Hi Waterdrop,

I gave the water a full check today and the nitrate is through the roof. The scale is a series of pinks and purples with a maximum of 110. The reading was so high that the water turned orange. Nitrite was 3.3 and pH was 7.0. Strangely, the ammonia was not down to zero today. Will the high nitrate affect the processing of ammonia? Looks like I may need to do that water change.

 

[waterdrop]

Sounds like full water change time. Nitrates that high will definately slow the N-Bac processing but also may have an effect on the A-Bacs. Your pH is also now lower so a big water change is going to have positive effects in many ways. Don't forget to recharge ammonia after doing all the normal water change things.

~~waterdrop~~