Corys

[Barneykirk3]

Hi Byron my GH is in the region of 4.2deg which equals 75ppm. I have checked all listed and they fit the gh.

 

[Byron]

Hi Byron my GH is in the region of 4.2deg which equals 75ppm. I have checked all listed and they fit the gh.

OK. The KH is likely also low, so this means the pH will almost certainly lower naturally as the tank biological system establishes. I'll explain.

Organics accumulate continually in an aquarium with fish. The fish excrement is the largest source, but there are others like organics in the tap water, uneaten food, decopmposing plant matter, etc. If wood, peat, or dried leaves are present, they contribute organics.

As organics increase, they are broken down by various types of bacteria, primarily in the substrate. We are not here talking about nitrifying bacteria, but different types. As this occurs, CO2 is produced, and in turn carbonic acid. This acidifies the water, and the pH lowers. This is normal, and not usually a problem. We can offset this with water changes, not overfeeding or overstocking, live plants, keeping the filter clean, and vacuuming the substrate in open areas.

The extent to which the pH lowers is determined by the above process but also the "buffering" capability. The GH and KH, especially the latter, work to buffer the pH, preventing fluctuations. The higher the KH, the greater the buffering capacity. Here, the GH is low, and likely the KH is too, so there is less "buffering" capacity. Not a problem, but worth knowing. The afore-mentioned water changes, etc all contribute to keeping this stable.

You are considering soft water fish, so no problems with GH. The pH at 7 will likely lower, over the next few weeks (once fish are present), so there will be no issue about pH. Not that there was anyway, but some of the species will be better with a lower pH, so this is going to move in the right direction for what you are planning.

Knowing the GH, I see no issues with any of the fish. I was previously wondering about GH because a few of the species are more sensitive, but that as I say is not going to be an issue.

I'll let you come up with a shortened list, and comment if I see anything I haven't already mentioned. Feel free to ask questions.

 

[Barneykirk3]

Hi Byron

Well we are pretty set on Panda Cories and Neon Tetras. Someone i spoke with reckoned another school maybe harlequins but things in my list would work too. He also suggested getting a couple of non schooling fish like dwarf cichlid, guppy. platy and bolivian ram. I know the guppy and platy are no good as they like hard water. Do you think 3 schools and a couple of single fish is about right for my tank. Any thoughts on what dwarf cichlid or ram might work, or any other suggestion?

Thanks

 

[Byron]

Hi Byron

Well we are pretty set on Panda Cories and Neon Tetras. Someone i spoke with reckoned another school maybe harlequins but things in my list would work too. He also suggested getting a couple of non schooling fish like dwarf cichlid, guppy. platy and bolivian ram. I know the guppy and platy are no good as they like hard water. Do you think 3 schools and a couple of single fish is about right for my tank. Any thoughts on what dwarf cichlid or ram might work, or any other suggestion?

Thanks

One thing to keep in mind here, is that both Corydoras panda and Paracheirodon innesi (Neon Tetra) like cooler water than some "tropicals" so that is a good combo. I would say for these two species around 23-24C/74-75F would be sufficient. So this means additional fish need to be similar. This suggested temp can go up but only a degree or so.

Before getting to additional fish, another diversion about temperature. Because fish are ectothermic, temperature is the driving force of their metabolism. The higher the temperature, the more energy the fish uses just to maintain its normal internal processes, which are many and complex. So the higher the temperature, the harder the fish is working, and that causes stress plus it literally wears the fish out sooner. So temp is very important. Ranges given by reliable sources usually intend for the fish to be somewhere in the mid range long-term; the upper and lower limits are what the species should be able to tolerate but hopefully not permanently.

The fish in the initial list should have no issues with my suggested temperature. Cichlids are a bit different, depending upon species. They also carry other issues. If you get a pair, or a harem as some dwarf cichlids like, you will obviously have spawning. Dwarf cichlids generally find cories a nuisance, and even in large tanks (4-5 feet in length) I have had cories pecked and prodded to distraction by very small female Apistogramma defending their egg clutch or fry shoal. Sometimes this carries over to non-spawning times too, because the cichlids are substrate feeders and the cories are always "in their face" as it were.

A single Bolivian Ram would be a good choice. This species is believed to live in isolation except when spawning, and I had a beautiful male in my 115g tank for 8 years. He owned the tank, no doubt about that, and it was interesting that he never fussed over most of the cories, but spotted species seemed to annoy him at feeding, though never otherwise. In the confines of your tank, this is about the only cichlid I personally would consider. I would up the temp to 24-25C/76-77F, which shouldn't be problematical.

Your pencilfish would be a good match, with the neons and cories (and a Bolivian). N. beckfordi prefers to remain in the upper level among floating plants, and would fill that space nicely. [Floating plants, or plants at the surface, or overhanging vegetations are essential for most of these fish, but pencils need them.] Temp is fine, I might keep it at 24C/76F here. Or hatchetfish (but not both), have you though about them? The best for this situation is the Marble, Carnegiella strigata, in a group of 9-10. This is a fish that always does better with more of them, and I wouldn't go less than 8-9 with hatchetfish. Cichlids have no issues with hatchetfish.

The Harlequin Rasbora will fit in, no issues there with what we're discussing. They tend to remain mid-water.

 

[Barneykirk3]

Thanks Byron all the information is very helpful. I will work through it and any more questions I will let you know.

Thanks.

 

[Barneykirk3]

Hi Byron

Can I just check if I went Marbled Hatchetfish, would the neons , corries or the ram try and nip their tails? Is there anything in my list that would?

 

[fluttermoth]

Hi Byron

Can I just check if I went Marbled Hatchetfish, would the neons , corries or the ram try and nip their tails? Is there anything in my list that would?

I know I'm not Byron, but I have kept all those fish together, and you won't have any issues, as long as you have a decent number of neons, which can be nippy if not in a large enough shoal

 

[Barneykirk3]

I know I'm not Byron, but I have kept all those fish together, and you won't have any issues, as long as you have a decent number of neons, which can be nippy if not in a large enough shoal

Any info always helps. Thanks for the message was thinking of say 10 neons is that big enough?

 

[fluttermoth]

Any info always helps. Thanks for the message was thinking of say 10 neons is that big enough?

Yes, although, as with all shoaling fish, the more the better

 

[Barneykirk3]

will try and get as many as is safe to do so. Looking like Hatchetfish, Cories, Neons and a single ram at moment in a 125 litre tank, so seems I might get a nice school of each.

 

[eaglesaquarium]

Hatchets are jumpers, so be sure to have a good fitting lid.

 

[Barneykirk3]

Well lid is in 3 parts but covers tank, should that be ok?

 

[Byron]

I agree that the fish in post #21 (and #25) should be compatible with no issues, in decent sized groups. It was the pencilfish species mentioned previously that would be a problem.

Good tank cover is necessary; more than once I have gone into my fish room in the morning and found a hatchet on the floor, when I have foolishly forgotten to close the cover after feeding the day previous. Hatchets living at the surface can get "spooked" by fish moving about under them...and cories for example are nocturnal, meaning they will be scampering about in pitch blackness. And the hatchets being startled jump to escape the danger, and out they come. Be careful during water changes too; I have hatchets in two tanks now, and I always lower the water a few inches before removing the cover. Just a couple weeks ago one of my beautiful Platinum hatchets jumped out before I had fully closed the cover following the water change. I suspect the shock of the fall, even though onto carpet and I was right there when it jumped so put it back immediately, was sufficient to damage him; and since the following morning I have been short one of the species so it was likely the one that jumped that died during the night.

Don't have more than just enough space in the cover around heaters and filter tubes. You would be surprised at how a fish can get through what would seem a near-impossible opening. My marbles used to jump and manage to get in between the two cover glass panes on the tank, so I moved them into a tank with a different cover. I lost two one night, and one another time.

Byron.

 

[Essjay]

The tank in question is a Juwel Rio 125. This doesn't have cover glasses, so Byron's problem won't be repeated.
It is quite possible to do a water change by lifting the front flap and pushing the light bar backwards, so that the rear flap stays closed and just overhangs the back of the tank. This will reduce the amount of surface area exposed. I used to have a Rio 125 and that's how I did water changes.
The tank does have two cut outs in the trim at the back. They can can be plugged with something like filter wool to stop fish escaping - but be careful not to knock them out when doing a water change.

 

[Barneykirk3]

I am quite worried about the fish jumping out, as I am sure my dog would like a taste but reading the posts maybe I'm worrying a little too much.