Potential Overheating

[Mr Bliss]

Hi everyone,
my new planted tank has been there for about a week now (without fish at this point, of course), most of the plants have started growing fantastically, and there isn't a hint of algae yet, but I notice that the temperature rises to 29C (84F) daily, because of the metal halide and halogen lights (there's no direct sunlight on the tank, or indirect for that matter). I wouldn't be worried, if it weren't for two things:

1) Unstable temperature. The temperature drops a couple of degrees every night when the lights are off. I figure this can be a good thing for oxygen balance, but I worry that my future fish won't like the fluctuation.

2) Our apartment gets really hot really fast. On hot summer days I think the tank temperature could easily go up to 30C (86F). This seems excessive for many fish.

It's a 55g open top tank (low pH, soft-ish water, although the values have yet to settle due to the tank being so new), and I plan to install a fan on top, operating on the same timer as the lights, which might balance out the night/day fluctuation. I'm not sure how much it'll help, though, as the air circulation above the tank is already pretty good. In any case, should the fan fail for some reason (e.g. moisture) I'd like to minimize the risks of a disaster, and I figure selecting temperature-tolerant fish and shrimp species in the first place would be a good start.

The fish and critters I want to have (but am not sure if the tank temperature allows it):

- 2 - 3 Bolivian or German Blue Rams, or a male & 2-3 female Apistos
- A school of 10 or so tetras or rasboras that won't jump out of an open top tank. Still need to do some research on the "jumpiness" of various species, but would prefer Nematobrycon palmeri (Emperor tetra), Hyphessobrycon rosaceus or H. pulchripinnis, or tetras with similar looks.
- 1 - 2 Bristlenose pleco
- A bunch of red cherry shrimp
- A generous amount of trumpet snails

Any big no-no's on this list in terms of the temperature? The Rams' recommended temperature range reaches 30C in the literature, but I'm not sure how well they can take the fluctuation in the temp.The biggest question mark I think is the bristlenose, since I believe they like slightly cooler, oxygen-rich water. Maybe I should forget about them and get a pair of pearl gourami (Thrichogaster leeri) instead, since I know from experience that they can tolerate high temperatures and remain seemingly happy (tank heater malfunctioned a few years back and it took me a while to notice this; the gouramis actually became more colorful and active while everyone else in the tank looked a bit ill). Problem is, I really like bristlenoses and would like to have them if I knew they'll be happy. Yet I'm also worried that the bristlenoses might stress my rams/apistos, argh... Any opinions on suitable tetras? How about the red cherry shrimp? I've read that the Amano shrimp is extremely temperature-tolerant, but haven't really been able to find out much about the red cherry.

Still got time to research this, since it's going to be weeks before I start gradually stocking, but any advice/opinions/anecdotes would be appreciated. And sorry about the long post, I tend to ramble.

 

[minxfishy]

In the wild the temperature would drop over night anyway as the sun wasnt heating the water, so a small fluctuation over night wouldnt be a problem.

I would try to minimise the higher end of the scale though as some fish dont like the high temps as you know, maybe have a period of time when the lights are off during the day (also apparenty good for the interference of algae growth is to have the lights on timer to turn off for a period of 2 hrs during the 8 - 10 a day)

I would not add cherry shrimps with the rams (not sure on apistos) because they would probably not survive long - if they did, would live in hiding most of their life.

 

[Mr Bliss]

I would not add cherry shrimps with the rams (not sure on apistos) because they would probably not survive long - if they did, would live in hiding most of their life.

Ooh that's a good point. I already ruled out Kribs, but I hadn't thought of the rams possibly being incompatible. Need to do some research on Apistos + shrimps I guess. Do you reckon Amano shrimp would be OK with rams, though?

 

[minxfishy]

Hmmm tough call, larger I know, but again quite possibly hunted down

 

[Mr Bliss]

OK so after googling a bit I ran into several anecdotes of various Apistos hunting down smaller shrimp and decimating entire populations of Amano shrimp when the little cichlids decide to breed. Also plenty of anecdotes of Apistos getting along with shrimp just fine. I don't really want to experiment when the lives of the little critters are at stake, though.

So much for the planned shrimp then.

 

[minxfishy]

Ah you see, thats where MTS (multiple tank syndrome) comes in. You realise you cant keep all the fish you want in one tank, so off you go to buy another........................an another.....................an..............well you get my point

Nope no shrimps in that tank

 

[oakes]

hi, i keep a variety of fish including tetras. The summer days here can get very hot and a couple of times my tanks have peaked at 32C. I have not lost any fish, though perhaps luck played a part. I did read that neons will die if temp exceeds 29C. Mine survived, though they were definitely not happy. I keep bn plecs too and they were fine. But it's possibly only a matter of time before i lose fish, and i'm considering purchasing a chiller before next summer. As far as fluctuations, i don't believe 2C would be an issue, though rams might be more sensitive to this? I see the open topped tank as more of an issue, any tetra has the capacity to leap out if startled. Perhaps more prone to this would be the faster elongated types like rummynose etc. Pencilfish are also known as leapers, and danios and many rasboras would be risky. Try to research the less timid or active types that like warmer temps. Better still can you cover the top with a screen that allows air flow?

 

[gaz gun man]

you should be ok with small temperature fluctuations, as already said in their natural habitat they would be cooler at night.

If your tank does get really warm open the top and keep the lights off