[yellowbrickroad]

Hi again, thanks to everyones help a few days back I now have a better understanding of how to stock my first tank to suit my water parameters (ph 7.4, gh 17-21 (awaiting liquid API test so I can check accurately) and nitrates in tap water are high (20-30ppm - will resolve this before adding fish).

I know I will be getting Corydoras aeneus, probably albino variety. But I've been going around in circles figuring out what else to get that will be ok in my hard water and will not be aggressive in a 20g tank. I've got it down to a school of either cherry barb (worried about possible territorial behaviour/aggresion), zebra danio (bit too fast for what I wanted) or white cloud mountain minnow. My other thoughts are to make it a cory only tank, or corys and a couple of same-species male livebearers.

I'm also unsure of which order to add them; I've read that cory's don't like a new tank, but also that they can take a few days to settle down, so I'm wondering if I should get them first so they can settle without annoying the other fish (especially if I get the cherry barbs).

Any thoughts are very welcome

 

[Byron]

Water is suited to livebearers, though a 20g will limit these as many need more space. But platy, guppy, endlers livebearer are possible. Or for something completely different, there are a few cyprinids that do well in these parameters, have a look at those in the profiles. The Emerald Dwarf Rasbora comes to mind. The white cloud mountain minnow would be OK, remember they need cooler water (i.e., room temperature) and this would be OK with Corydoras aeneus too. Pristella Tetra is a characins that would work. And some of the smaller rainbowfish perhaps.

The above is taking the present water parameters into account. Depending how you resolve the nitrate issue, that may result in less GH in the water, opening up other options for fish.

Byron.

 

[yellowbrickroad]

Thanks Byron, the emerald dwarf rasbora look lovely but I've never seen them for sale where I am. If I went for livebearers I was thinking platy. There are a couple of species of tetra I like, black widow and head and tail light especially, but I'm concerned about fin nipping. If the white cloud mountain minnow would be ok with bronze cory I might go for those. I was thinking a school of 10, does that sound ok?

Lou

 

[Byron]

Thanks Byron, the emerald dwarf rasbora look lovely but I've never seen them for sale where I am. If I went for livebearers I was thinking platy. There are a couple of species of tetra I like, black widow and head and tail light especially, but I'm concerned about fin nipping. If the white cloud mountain minnow would be ok with bronze cory I might go for those. I was thinking a school of 10, does that sound ok?

Lou

While all named fish would work with respect to water, one must remember the tank size is only 20g. The Black Widow Tetra should be in larger quarters, as it needs a group of say 7 or more and it does get a decent size; otherwise it might get quite nippy. Tank space being small (to the fish) and/or insufficient fish in the group can both cause increased aggressiveness.

The Head and Tail Light Tetra is fine. I would have a group of 8-10. For the minnow, 10-12. A group of 6 of the cory with either of these.

Byron.

 

[yellowbrickroad]

Sorry for my slowness in thanking you for your response. I had decided against the black widow tetra for the reasons you mention, although I'd like them one day when I have a bigger tank as they're so beautiful. I've now tested my GH with the API liquid test and it's 16, so a little lower than I'd thought. Does this open up more options? I originally wanted harlequin rasbora but discounted them due to GH. I see in the profile up to 15 GH is recommended; would 1 dh extra be harmful to them?

I have now found somewhere that stocks emerald dwarf rasbora but from the profile I'm wondering if they'd be unsuitable with bronze corydora? As for tetra, I'm a little nervous about getting them as I keep reading about tetra being nippy, but I'm still open minded. My cycle seems to be going ok, I'm currently having big nitrite and nitrate spikes, once the nitrite goes down I'll water change, add plants and keep an eye on things for a few days (I plan to add ammonia to 1ppm during this stage) and then get my first fish so I've still got a few weeks to decide.

 

[Byron]

Sorry for my slowness in thanking you for your response. I had decided against the black widow tetra for the reasons you mention, although I'd like them one day when I have a bigger tank as they're so beautiful. I've now tested my GH with the API liquid test and it's 16, so a little lower than I'd thought. Does this open up more options? I originally wanted harlequin rasbora but discounted them due to GH. I see in the profile up to 15 GH is recommended; would 1 dh extra be harmful to them?

When giving ranges, one has to stop somewhere; 1 dGH is not going to matter much.

I have now found somewhere that stocks emerald dwarf rasbora but from the profile I'm wondering if they'd be unsuitable with bronze corydora?

Why would you think this? If due to the info under Compatibility, that basically refers to upper water fish. I've had a shoal of this species for a couple years now, and they don't bother substrate fish and haven't done so with upper fish either, at least not that I've seen. But all things considered, I would prefer to have this fish in its own smaller tank. It has never coloured up like the profiles, and I have 4 males and 5-6 females.

As for tetra, I'm a little nervous about getting them as I keep reading about tetra being nippy, but I'm still open minded.

Some tetra species are prone to be nippy by nature, almost always; sometimes larger groups in spacious tanks can reduce this or confine it within the species. Serpae, Black Widow, and a few others.

But the majority are usually OK if they are in a good group. And have sufficient space. One can't put temptation in front of them though, this will often cause them to show a nippier side.

My cycle seems to be going ok, I'm currently having big nitrite and nitrate spikes, once the nitrite goes down I'll water change, add plants and keep an eye on things for a few days (I plan to add ammonia to 1ppm during this stage) and then get my first fish so I've still got a few weeks to decide.

Once the plants are in, I would not add any ammonia.

 

[Hallyx]

Once the plants are in, I would not add any ammonia.

Why's that, Byron? I thought plants liked ammonia.

 

[Byron]

Why's that, Byron? I thought plants liked ammonia.

Ammonia is toxic to all life, be it bacteria [except the types that use it of course], plants, fish, animals, humans.

It is true that aquatic plants can use ammonia/ammonium as their preferred source of nitrogen. And they can also use ammonia for other things [see below]. But plants can be harmed and even killed by ammonia. Walstad writes that some sensitive species are harmed by ammonia as low as 1 ppm, while others can go as high as 26 ppm. And these numbers are for ammonium, the less toxic form.

Straight ammonia [NH3] can be detoxified by plants. Ammonia can enter the cell by diffusion across the membrane, and then may combine with a hydrogen ion [H+] and convert to non-toxic ammonium [NH4] which can be stored in cell vacuoles. But plants can also us the ammonia [NH3] to synthesize proteins. In this case the ammonia is combined with carbohydrates to form amino acids. So fast growing plants can tolerate higher ammonia because they have more carbohydrates to combine with it, plus the higher need for ammonium as a nutrient.

But rather than risk overdoing it, my approach is to keep ammonia limited. It is quite interesting how much ammonia naturally occurs in an aquarium from the breakdown of organics. I have a 20g tank that I use for new fish so it often is fishless for several months. It is planted with pygmy chain sword, floating Pennywort, Frogbit, and sometimes daughter plants from the larger swords. The plants manage well in spite of there being no fish in the tank. So ammonium and CO2 is obviously being supplied solely from the breakdown of organics, even though there are no fish to provide organics. Increasing ammonia far above other nutrients might cause toxicity; this is just my surmise.

Byron.

 

[Hallyx]

Thank you, Sir. I'm glad I asked.

 

[yellowbrickroad]

I was going to ask the same so thanks for the info Is there no danger of my bacteria colonies that I've been growing in the cycle dying, given that this is a brand new tank? There will be a few days between me getting the plants and the fish.

Regarding my wondering about the emerald dwarf rasbora, yes it was the part in the profile about compatibility; I didn't realise it did not apply to substrate fish.

 

[Byron]

I was going to ask the same so thanks for the info Is there no danger of my bacteria colonies that I've been growing in the cycle dying, given that this is a brand new tank? There will be a few days between me getting the plants and the fish.

Regarding my wondering about the emerald dwarf rasbora, yes it was the part in the profile about compatibility; I didn't realise it did not apply to substrate fish.

I wouldn't worry about the bacteria. You want the plants using the ammonia/ammonium, and they out-compete bacteria all else being equal. Add fish slowly, just a few to start with, and there will be no issues. And, nitrifying bacteria are not quite as "delicate" as some believe.

 

[yellowbrickroad]

Thanks Byron, I'll admit I'm finding it a little confusing, as a complete newbie, that there seem to be 2 schools of thought; fishless cycling or planted tank. Is fishless cycling more designed for tanks with fake plants? Probably if I'd come here first I'd have gone for the fully planted option but now I feel a little like I'd have wasted the last few weeks fishless cycling! as I said in a previous thread, I'm not confident yet maintaining the plant's health so I'd rather start slowly with plants and see what grows well in my water and with my lighting, so hopefully my fishless cycling efforts won't have been completely wasted! Sorry that this is now a bit of topic from my original post. Thanks for all your advice.

Louise

 

[Byron]

Thanks Byron, I'll admit I'm finding it a little confusing, as a complete newbie, that there seem to be 2 schools of thought; fishless cycling or planted tank. Is fishless cycling more designed for tanks with fake plants? Probably if I'd come here first I'd have gone for the fully planted option but now I feel a little like I'd have wasted the last few weeks fishless cycling! as I said in a previous thread, I'm not confident yet maintaining the plant's health so I'd rather start slowly with plants and see what grows well in my water and with my lighting, so hopefully my fishless cycling efforts won't have been completely wasted! Sorry that this is now a bit of topic from my original post. Thanks for all your advice.

Louise

I've only ever gone with live plants from day 1. But fishless cycling is worth it if there are no live plants. If you have some fast-growing plants, and here floating are ideal, a few initial fish will have no issues.