Hi

I have previously kept a Betta in a small tank, we have moved to bigger place now and have a small child so we thought it would be nice to get a bigger tank.

I've just bought a second hand Juwel Rekord 96. I kept the old gravel and some of the filter from the old tank and have put some plants in and have just added ammonia to start a fishless cycle. Am going by the article on here which is really useful for the amount of ammonia to put in.

I am aware it will take a good few weeks until the process is complete having done it before with the smaller tank.

I am conscious of not overstocking so I was wondering how many fish we would be looking at for a tank this size. We like the idea of something like Zebra Danios, can anyone suggest any others that are good to mix with those and any that should be avoided.

Thanks.

I will likely be popping back in with questions as my cycle progresses.

Hi and welcome,

To work out how many fish you can keep, take the volume of the tank and knock off 10% for displacement by gravel, ornaments etc. You can keep 1 inch of fish (at projected adult size) per gallon (or 2.5 cms of fish per 4.5 litres) initially. Once the tank matures, if all is well with the water quality you can increase a little on that to an absolute maximunm of 2 inches per gallon or 1cm per litre.

To decide on fish you might like, you need to find out what the pH and hardness of your tap water supply are. pH should be tested straight from the tap and a cup left out for 24 hours and tested again to see if it changes (it often does). Hardness can be tested using a gH/kH test kit, or you can get an average for your area by visiting your water supplier's web site and typing in your post code.

If you really want tropical fish, then avoid Danios as they are temperate and need cooler water than most tropical fish so would limit your choices.

Thanks for the reply.

My pH from the tap is 7.6. I have some sitting out to test tomorrow.

This is the info from my water company though I am not sure which figures are important to me.

HARD WATER
The area supplied by Veolia Water Central has 'hard' water. The hardness occurs naturally and is characterised by the presence of high levels of calcium and magnesium, which are good for healthy teeth and bones.
CALCIUM 128 mg/l
Calcium is the principal constituent of hardness.
TOTAL HARDNESS 320 mg/l
Total hardness is usually expressed in terms of calcium carbonate and is measured in milligrammes per litre (mg/l) or parts per million (ppm). The recognised classification scheme we are using is: 0-75 soft, 76-150 moderately hard, 151-300 hard, 300+ very hard. Your water is very hard.
Degrees English (or Clarke) 22
This hardness measurement is used on some British appliances.
Degrees German 18
This is used on some German appliances.
Degrees French 32
This is used on some French appliances.
MILLIMOLS 3.2 mmol/l
Millimols per litre. Some appliances refer to water hardness in millimols per litre (mmol/l).
FLUORIDE 0.175 mg/l
Fluoride naturally occurs in the water in many areas. Veolia Water Central does not add any fluoride to your water. Fluoride is measured in milligrammes per litre (mg/l).

The two expressions of hardness you're most likely to see on care sheets for fish are mg/l (which is the same as ppm) and dGh which is German degrees of hardness. These two in your report:


Quote:

That's very hard water and it's likely (though not certain) that you will find the pH has risen when you check it after 24 hours standing.

Given your location the water is as we'd expect and it does limit you somewhat in terms of species that will suit the water.

Until we know the pH too we can't be very specific, but your best options for tropical fish that will thrive in those conditions would be livebearers such as Mollies, Platies, Swordtails and Guppies, or possibly, if they appeal, a small community of Tanganyikan shell dwelling cichlids.

Thanks for clarifying. I will update pH tomorrow. It would be nice to have a few different types of fish so I will need to research which of those will mix well together.

pH after 24 hours was 8.2.

Would the pH of the tank be different though, due to plants, substrate etc?

Unfortunately the pH of the tank is likey to remain similar to the tap level as you will be doing regular water changes once the tank is stocked.

Plants will have no effect on pH, substrate is unlikely to lower pH either, and common methods for achieving a minor reduction (peat, bogwood) won't work in hard water.

Additionally, a reduction in pH alone is not enough - if fish need a low pH they usually need softer water too (the pH is a reflection of the minerals in the water). Reducing hardness usually also reduces pH but can only be done by mixing the tap water with a suitable proportion of reverse osmosis water.

EDIT: An alternative is to run a temperate tank and have Danios as you originally planned, along with White Cloud Minnows. There are several variants on the standard Zebra Danio who will shoal together and a mix of those with a nice shoal of WCMM would look really good. These would all be happy with your water.

You mentioned that Cichlids may be suitable, would this still be the case with the readings after 24 hours?

Yes, in that size tank and with your pH/GH shellies would be fab for example (I'm still tempted with this species). Fantastic fish needing loads of snail shells and very endearing.

cathie certainly keeps them as well as a few others here, but they do populate I know, so rehoming youngsters may be an issue unless you have a good LFS you could speak to.

http://www.seriouslyfish.com/species/neolamprologus-brevis/

cathie sometimes has juveniles to rehome, perhaps PM her if you are near her location?

Thanks for this, would it only be the shell dwellers that were suitable or would any of the others be?

I currently have a gravel substrate so I am assuming I will need to change this.