Filter Flow Rate

25-26 should suit all your fish, although it could go a little lower. I tend to look at the range of temperatures my fish need and go for somewhere in the middle.

Can you adjust the flow of the filter?

The minnows don't just "tolerate" lower temperatures, they prefer it. All of my tanks are at 22- 23 degrees and I've never had any problems. The saving in electricity can be considerable, though it won't make much difference with only one tank. Most of the information about conditions fish need are just passed without question from one book or web site to another without question, even if they are wrong.

I would say your filter relative to tank size really is rather too powerful for most fish. You can slow down the rate (assuming it can't be adjusted) by tying a piece of foam over the exit. Most fish can cope with fast flow but they do need a rest, forcing them to endure it at all times is likely to stress them out. The flow at the bottom of the tank should be much slower than at the top, that's how things are in nature and most fish stick close to the bottom in fast water to get out of the flow.

Hi BDS,

Welcome!

Your experience seems to be fairly typical of what happens – often, generic pet shops have not heard of the fishless cycle or tend to say that leaving the tank alone for a few days is the fishless cycle, while aquatic shops tend to be more aware of what it involves but often dissuade from it for what sounds fairly plausible reasons, especially to someone fairly inexperienced. In terms of sound advice (or lack of it), what is of particular concern is that they sold all 18 of those fish at once in conjunction with knowing that you’d be doing a fish-in cycle albeit with the aid of that product – if they’d sold one of those shoals (probably not the neons which are best suited to more mature aquariums), then that would have been more sensible.

However, well done for keeping up the regular water testing and water changes which are and will be crucial to try to keep ammonia and nitrite at 0, and nitrates low (ideally under 20 if at all possible). The evidence for products such as ATM Colony, Tetra Safestart, Fluval Cycle, etc, is quite variable, so keep bearing that in mind and keep up your regime of water testing and water changes over the next month to six weeks, just to ensure that no “spike” occurs when you might be least expecting it or just when you think that all is safe – there is a greater degree of risk of exposure to ammonia/nitrites and high nitrates with fish-in cycling than with fish-less cycling, hence the need for scrupulous monitoring, and especially with that number of fish.

A few specific suggestions/queries:
•   I’d recommend doing the testing at least twice a day eg first thing in the morning and last thing in the evening and, if at all feasible, during the daytime as well. 
•   What size of daily water changes are you doing?
•   What water dechlorinator are you using? Seachem Prime has the advantage of detoxifying the effects of any ammonia/nitrates/nitrites on the fish for 24hrs, and it might be an idea to use that for the next while at least until you’ve got through the cycling process, after which you could always return to using whatever other product you may have bought.
•   Underfeeding (eg half a flake per fish per day) during this time, so 9 flakes per tank, would also be wise, in order to minimise the amount of ammonia produced by the fish.

As for the internal filter, what you could do is cut a piece of aquarium sponge to fit in the filter nozzle and keep it in place with one of those twisty wire things (sorry – forgotten what they’re called!) that goes round the top of a loaf of bread. Alternatively, a spray bar can help.

Hope this helps.

You might find you have problems with the dwarf hairgrass but that's more to do with its growth requirements than the water flow. All the rest should be fine. What type of vallis is it? I have NEVER been able to grow the twisted variety, it just dissolves!

I received a bottle of Seachem Prime in post today, so will add that to the water change. With those levels I was thinking of another 30% water change today? I'm feeding them very little (minute pinch that is gone in about a couple of minuets )every other day, is that about right?

Excellent re Seachem Prime, and suggestion for feeding sounds about right although you might be better giving half that amount every day ie that is eaten within one minute. 30% (or indeed anything up to 50%) water change is probably fine, if that can get/keep the ammonia and nitrite down to 0.

Thank you Sue, I may just order the sponge online to be safe. Ammonia is at zero at present and I'm testing  for nitrite on a regular basis.

Thanks for all your speedy replies. I'll post a photo of my aquarium setup in the gallery, sometime.

Sympathies with the need for frequent water changes. I over cleaned my filter once and started off a mini cycle and ended up doing water changes twice a day. It'll all be worth it in the end though.

I suppose what I'm saying is this normal?

Ok, thanks Sue. I thought as much but needed confirmation. I'm prepared to wait and continue the water changes. I've just ordered another nitrite testing kit as I've nearly exhausted the previous one . My little fish are doing fine with this regime  .

You should be using the higher values.

There are 2 ways of expressing the concentration - as ppm or mg/l of the whole NO₂ and NO₃, or as the concentration of just the nitrogen (N) part. The majority of test kits measure the whole NO₂ and NO₃; yours is unusual in measuring just the N. The concentrations in all the cycling methods I've ever seen use the whole NO₂ and NO₃.

UK water companies also use the whole NO₂ and NO₃ in their water quality reports.



So your tank readings are nitrite = 0.825 and nitrate = 11.
Nitrite is a bit on the high side, try to keep it below 0.25 on the NO2 scale, which would be 0.075 on the N02-N scale.

Your nitrate reading is also quite low - most people have more than that in their tap water. Have you tested your tap water to see what yours is?