Fish Tank Cycling Query

The problem with biological things is they never follow procedure to the letter.

I would treat things as though you'd never had that 0 nitrite. Go to stage #7 - testing every 2 days and wait for two zero ammonias. So test on Saturday, then Monday. If both are zero add 1ppm ammonia and continue testing every 2 days. If you don't get 2 zero ammonias, just carry on testing every 2 days until you do.

I am doing a fishless cycle as well, the first time I've used this new method. I am fed up with the internal in my betta's tank falling off the glass. He sleeps on it, which might have a lot to do with that. So I've got a sponge filter powered by an air pump. Unfortunately, there is no way I can use the internal's sponge so I'm doing a full fishless cycle in my quarantine tank. I haven't even squeezed any media into the QT as I want to see what this method is like. I'm using just 2ppm ammonia as the tank is 26 litres with just one fish and a small snail so they won't make 3ppm, probably not even 1ppm ammonia.
Yesterday (Thursday) was day 16, the fifth of the 3 day tests and the ammonia had dropped from 2 to somewhere between 1 and 2, and nitrite was 0.25. Next test is Sunday so I'm keeping my fingers crossed.

You are well ahead of me.

Well done!

If you can't get fish straight away, add the 1ppm dose of ammonia every 2 or 3 days until you are ready to go shopping, then do the big water change either the day before or even just before you go.

In theory you can get all the fish at once provided the shop will sell you that many. In practice, it is better to leave sensitive fish until the biofilm has developed a bit more, so wait a few weeks for those fish. I would class cories in this group.

Redmoor wood does take ages to sink. Either leave it soaking a bit longer (it will sink eventually, I have several pieces and the bigger ones took weeks) or fasten it to a piece of rock to hold it down till it stays down by itself.

As for your soft water, 25% twice a week would be better. Monitor the pH daily at first then you can see if you will have problems. My KH is 3 and provided I do water changes of at least 25% every week without fail I have no problems. You could try getting a sample of tap water tested for KH at a fish shop then you'd know if you really do need to add crushed coral or whether water changes will be enough.

Using hot water from a combi boiler is fine with fish. It's the older systems like ours you have to be careful with. We have a hot water cylinder that is filled from an open topped tank in the attic, and it is that tank that can cause problems. Because it is open topped (just a loose cover) all sorts of things can get into it eg dead mice, and decomposing mice in hot tap water won't be good for fish. It's also why you should never, ever use hot water like this for cooking.

Rummies can be sensitive, but so can a lot of other tetras. Looking at your water company's table higher up, at least you don't have to worry about nitrate 
Are you set on rummy noses or are you happy to go for something else (and maybe get rummy noses in the future if you catch multi tank syndrome)?




Multi tank syndrome - an affliction of fish keepers characterised by the almost uncontrollable desire for more and more fish tanks. In my case it is only kept in check by a husband who has no interest in fish 

I've just googled cricket dust to see what you meant and the links I found say it is a dust you apply to live reptile food so the reptile will eat it. If you put that in your tank you'd probably get a very cloudy tank. Something a bit more substantial than a powder is what you need - though if you mean something else by cricket dust can you explain what it is please.

Things people use are crushed coral, lumps of coral, shells, limestone (tufa) rocks - if you wanted any rocks in the tank for decoration get limestone/tufa and kill two birds with one stone.
This is also the reason for doing two water changes a week, and smaller than usual ones. If you remove a lot of water from the tank that has calcium carbonate dissolved in it and replace it with water that has virtually none, the change in hardness will affect the fish. More frequent, smaller water changes means less hardness going out of the tank in one go.

There is something else you could try. People who use RO water need to add minerals back into the water so they use remineralisation salts. For example Tropic Marin salts. Be careful as there is a marine version too.
If you wanted to use this you would need to add it to the tank before getting fish, and you'd need a hardness testing kit to make sure you got it to the hardness you wanted. I would not suggest trying to make the water very hard, just raise the KH enough. Somewhere about 4 degrees (70ppm) would stop a pH crash.
When doing water changes you would need to add the salts to the water before it goes in the tank. Again, you'd need to test it for the first few times, then you'd get to know how much you'd need to add.



Both glowlights would be fine, and a bit hardier than rummies.

Re the redmoor wood and pH, a thought occurs to me. Have I suggested testing a sample of water that has stood for 24 hours? Just run a glass of water, test straight away then leave it standing for 24 hours and test again. You'll probably find the two tests are different. Mine goes up by 0.2, other people have much bigger changes. Standing allows dissolved gasses to gas out of the water, which can change the pH.


If you want hardy fish that will cope with inexperience, and will live in a wide range of water types, look at cherry barbs. I got some a few months ago, a mix of normal and albino. The albino males are orange and the females are yellow with red fins and red 'lipstick'. Mine came from Maidenhead Aquatics if you have one near you and want to go window shopping.

Maidenhead Aquatics is one of the better national chains, though as each shop has its own manager it can vary. MA has a list of fish that each manager can choose from and it is up the individual manager which fish he/she chooses from that list. So although almost all branches will stock the common (ie popular) species, the not quite so common will vary from branch to branch. Most will order in fish as long as they are on the list, so if they don't have them, just ask. Peacock gobies were on the list last year as the one nearest me had them in.
If you get peacock gobies, provide them with very small caves with ridiculously  small openings. I mean caves that are just about fish sized. They prefer these for spawning in. I had some a few years ago and they spawned in a 1 inch tall plantpot in the quarantine tank!

In that case, don't worry about the pH. It just occurred to me that the water in the bucket with the redmoor wood could have fallen because that's what your water does on standing, without redmoor wood. Since your tap water doesn't change on standing, it's the wood dropping the pH in the bucket. The effect should diminish over time. But it does mean that it is likely to drop the pH in your tank, so doing a big water change would alter the pH in the tank quite a bit - smaller, more frequent water changes would be better.

The gobies will breed in something bigger, they tend to like small entrance holes. If you could find something to reduce the entrance hole to almost the width of the fish, they'd be happier. With these fish it is dad that looks after the eggs, so the holes needs to be big enough for the male to fit through.
Read up on how to tell the difference between males and females - the best way is the shape of the head rather than colours on the edges of the fins, though bear in mind that the 'bulgy' head only develops at puberty and fish in the shop are usually youngsters. You need one male (or two males if the floor if the tank is easily divisible into two territories) and at least one more female than males. I mean 1 male and 2 or more females; 2 males and 3 or more females.



My cycle isn't going    It got stuck. 5 days with no change in ammonia or nitrite. I started with 2ppm ammonia as the tank the filter is going in has only 1 fish and 1 snail and that was probably way more than it needs. On day 16 I had ammonia between 1 and 2  and nitrite under 0.25 (just the merest hint of purple, I had to do a test on tap water to see the difference). Day 19 exactly the same. Then I got impatient and tested on day 21 instead of day 22 and got exactly the same again. There is no substrate in the tank and there were big white flakes and tiny brown bits all over the bottom. So on day 21 (Tuesday) I emptied all the water, refilled and added 3ppm ammonia (so it fits in with the levels in the method). This is quite easy when your tank only holds 24 litres. Next test day is tomorrow.
I last did a fishless cycle 3 years ago using the old method, and the ammonia reading fell on day 12 - which is why I'm getting impatient this time.

I'm still wondering what all the bits were  One thing does worry me a bit. This is a sponge filter powered by a brand new air pump. The airline tubing is turning yellow where it leaves the pump. Is there oil residue or some such leaving the pump and making its way into the tank and when it meets water turning into the brown dust? Though I suppose that by the time this cycle eventually finishes, all the 'loose' chemicals from the pump will have gone.

I usually seed a new filter using old media but that is not possible going from an internal with a rectangular sponge to a filter which uses a specially shaped cylindrical sponge. I could have rinsed out some dirty media from another tank in the water to add a few bacteria and hopefully speed things up slightly, but it is good for me to see what new fishkeepers, with no access to old media, go through 

I haven't exactly started again, I still have whatever bacteria have already grown in the sponge. It's just taking longer than 3 years ago. Maybe the water company have got better at killing bacteria since then 


Your pH drop during the cycle is for 2 reasons. First, the bacteria use KH to grow properly, and you haven't much to start with. Secondly, nitrite and nitrate are acidic and they react with carbonate, also removing the little you have. Once the KH has gone, there's nothing to stop acidic things lowering the pH.
In the bucket, the wood will leach acids such as tannic acid. This will react with the carbonate, removing it and with nothing to stop it the pH will fall.
The pH in the glass hasn't been affected because your water company does not add anything to alter the pH. It is common for some companies to pump carbon dioxide into the water. This acidifies the water and makes it less likely for calcium to be deposited in their pipes. Since you have very soft water this isn't a problem for the water company. Where carbon dioxide is added, it gasses out on standing, the water becomes less acidic and the pH goes up.




Oooh, and I thought my dwarf chain loaches were expensive  . That's the trouble with window shopping, there are just too many fish to choose from. The worst is getting your tank fully stocked and then the shop gets some new species in.

Only in the sense that they use ammonia as food so it never gets made into nitrate. But live plants are a Good Thing; fish do seem happier with them. If you aren't confident about your plant growing skills, there are some easy ones that even I have not managed to kill off.

The plants that work for me are those that grow attached to things rather than planted in the substrate. Look at java fern (there are a couple of more decorative varieties such as wendelov) and the various species of anubias. These plants have a rhizome which rots if planted though it is OK if the roots go down into the substrate. Just tie them onto your chosen bit of decor with sewing thread/fishing line until they attach themselves.
I've also had success with a plant called bolbitis. And there's hornwort for a quicker grower. That can be planted but it also grows well as a floating plant. Since you have some redmoor wood soaking, you could also try winding hornwort round that to anchor it. One end of my 50 litre tank is a tangle of hornwort wrapped round redmoor wood. The only downside with hornwort is that older stems drop their needle like leaves which then have to be hoovered off the substrate.
I've found it easier to buy these plants on-line as not many of my local shops stock them - they go for the ones that have to be planted.