Rainbow Darter tank - does it sound OK?

I've been trying to set up a darter tank for a little while now, and once September hits it looks like I'll finally have the time to do it.

HOWEVER, before I set everything up, I want to make sure I have the right conditions and tank for the little guys.

The plan is to use a 20 Long with a modified HOB filter to produce a high flow, like in the riffle tank article on this site.

Without a heater, temperatures will get to 79 during the summer, and drop to 60 or so during the winter. My city uses well water, which is fairly hard and stays about about pH 8-8.2.

There will be 6-8 rainbow darters, and possibly 10 of an appropriate shiner/dace species (suggestions appreciated, though I particularly like rainbow shiners). The low-flow corner of the tank will be planted with Elodea canadensis, which I've observed growing on the edges of small streams.

Does this sound workable? I'm a little concerned about summer temperatures.

My tank is very similar to your planned setup. I've got Elodea densa and Orangethroat darters (Etheostoma spectabile). The one thing I would recommend to you is to up the current by buying a powerhead. The plants and the lack of a circuitous current flow stream [a place for the water pushed out of the way to go to] mean that the water movement from merely a Hang-On-Back filter will be very low. And your darters won't be able to swim in the water column like swim-bladdered fish do if there isn't a strong current. In situations where current is too low, all they can do is sit on the ground. I was on a river Saturday and was astonished to see something that I thougth was minnows but turned out to be darters, swimming in the water column in the strong current. Because of that, I plan to buy an extra powerhead for my own tank as well (I already have one. But I think the darters would like another). So, yeah, to wrap this paragraph up, add a powerhead to your plan. *nods*

Why will your tank get to 79 in the summer? That seems a little high for just room temperature, especially inside a house. If it persists for hours at a time, your darters will lose their color and begin to be stressed out. That's not good for their health. But I don't really understand why your tank water would get that hot. Is the tank in front of a window? I need more information.

And here's a side note: I know you didn't ask me this, but I figured I'd add it. Your darters will climb up into the plants and occupy the entire up and down range of the tank if you have plants that span from ground to surface. The anarchis (Elodea densa) is a good example of this. It will reach the top of the tank. But the darter will be quicker to figure out how to jungle-climb if you give them some wiggly things at the surface to eat (like livebearer fry) and some ledges to easily ascend. My profile photo is of a female Etheostoma spectabile chillin' a foot off of the ground in my hornwort, waiting for swordtail fry to swim close enough so she can try to eat them. She climbed there from a combination of rocks and plants and mild, supportive current. It's nice having the darters occupy the whole range of the tank. And I think they enjoy it, too.

And from a combination of personal experience and these articles (1. http://www.thekrib.c...rate-jamie.html 2. http://www.thekrib.c...te-jamie.html#1 ) I recommend Special Kitty kitty litter as the substrate for your tank or as an addition to your substrate. It's great for plants.

Also, a tip for my fellow plant grower. The lighting you'll need for good plant growth is cheaper at a home improvement store than it is at a pet store. My 4 foot light strip (with 2 full spectrum 700 lumen bulbs) was $30 including bulbs at Home Depot. It's an overhead shop light that's mean to be suspended but that I just set on top of the tank. So that's what I chose to buy, instead of $120 in aquarium hoods and bulbs. (18 inch bulbs are $20, 24 inch hoods are $40 at my local pet store and online). It works great; the plants are growing like crazy.

Edited by Okiimiru, 10 August 2010 - 04:19 PM.

interesting stuff

Thanks for the comments!

A few responses:

79 degree tank water in the summer - I live in Northern Cali, and the outside temperatures are at over 100 outside with no shade. Inside, tanks get to the high 70s during the day, and cool off a bit at night. If I had my tanks exposed to direct sunlight or something silly like that, I don't really want to think about what the temperatures would get to....

HOB not providing enough flow - correct! However, in the excellent riffle tank article on this site, the author shows how you can "dam" the powerhead and provide only a small outlet. When combined with a gravel ramp and a correctly placed intake, the flow from the smaller outlet creates a nice current without the need for a submerged powerhead heating up the tank.

Elodea - glad to hear the darters would enjoy this.

So, in conclusion, I guess I'm still pretty worried about those summer temperatures.

Edited by Sticklematt, 10 August 2010 - 04:28 PM.

Your tank setup sounds good. I'd stay with 6 darters.

The temperature range will be okay if you make sure there is enough oxygen in the water. An airstone will do it for you. I don't think this is critical, but if you want, you could also run a small fan over the surface of the water. That will give you a little evaporative cooling. If you replace the evaporated water with cool water in the evenings, they will love it. They will really dig those cool temperatures in the winter!

I would also recommend Koralia powerheads. I use several of them, they are very efficient and run very cool. They don't seem to add any heat at all to my tanks.

I have a few rainbow darters in a community tank. The temperature has held steady between 74-76 nearly all summer. My rainbows are doing fine and have never shown any signs of stress. In fact I have a sculpin in the tank too (more temperature sensitive than the darters) and he has been fine as well. I do have a fairly high volume airstone that is keeping the tank well oxygenated. I suggest you add an airstone for your setup.

Also...I second Susan's recommendation on Koralia powerheads. I have one of those as well. All my fish love the current, and it doesn't seem to add much if any heat to the tank.

Edited by brookiechaser, 11 August 2010 - 06:53 AM.

I have a few rainbow darters in a community tank. The temperature has held steady between 74-76 nearly all summer. My rainbows are doing fine and have never shown any signs of stress. In fact I have a sculpin in the tank too (more temperature sensitive than the darters) and he has been fine as well. I do have a fairly high volume airstone that is keeping the tank well oxygenated. I suggest you add an airstone for your setup.

Also...I second Susan's recommendation on Koralia powerheads. I have one of those as well. All my fish love the current, and it doesn't seem to add much if any heat to the tank.

I'm somewhat reassured, and now that you mention it, I have kept sculpin at 76 without problems, but the same is not true for (threespine) sticklebacks....once they're above 72 they're toast, even with large airstones. Those guys are bulletproof in the 60s, but temps in the 70s just kill them.

When I lived in Georgia, I successfully kept darters and the water temperature would get into the low 80s in the summer. I think the issue really is oxygen content; my water was well circulated. Of course, it may depend in part on what species of darters you have. I don't remember exactly what I had; I don't think it was rainbows, but a variety of other species from waters with good current (i.e., not swamp darters).

I think you will get just fine circulation if you put the HOB filter on the side of the tank instead of the back. I have done that very successfully using a 20-L tank in the past. Water turnover was good, and the darters seemed to enjoy the current. An extra air stone probably isn't necessary - most of the gas exchange occurs at the water surface; the way an air stone typically helps is by gettting the water moving about, not by exchange through the bubbles.

I have had temperatures get into the low 80's during the day in my tank in years past without any difficulty for the fish, including cooler water or fast current species (Variegate Darters and Redside Dace). I think as long as you have good oxygenation you will be fine.

And your darters won't be able to swim in the water column like swim-bladdered fish do if there isn't a strong current. In situations where current is too low, all they can do is sit on the ground. I was on a river Saturday and was astonished to see something that I thougth was minnows but turned out to be darters, swimming in the water column in the strong current.

They can swim in the water column just fine without current or swim bladders. Some species are more adapted to it, which in our area would include Logperch and Blackside Darters. What river were you in, anyways?

Andy

They can swim in the water column just fine without current or swim bladders. Some species are more adapted to it, which in our area would include Logperch and Blackside Darters. What river were you in, anyways?

Andy

I was canoeing at Mohican, which is in Loudenville, Ohio. http://maps.google.c...F-8&sa=N&tab=il There were darters, I swear, swimming in a school in a riffle about a foot deep without resting on the bottom or pausing for breath. They weren't darting around; they were swimming like minnows. I was previously under the belief that darters were confined to short bursts of swimming, maybe up to a minute of swimming, but not continuously just like shiners do. But that's what they were doing.
My Etheostoma spectabile (orangethroat darters) don't do that in my tank. They swim for short bursts and then sit on the gravel again. I upped the powerhead flow but they just avoid it, not swim in it. *sighs*
I'm not sure what species of darter it was. I wasn't able to catch any, because I was with normal people (not fish lovers) and we were "canoeing" and not "fish capturing", so I didn't bring a net.

Edited by Okiimiru, 11 August 2010 - 02:51 PM.

There are probably some sweet darters left in that river and sweet herps in the hills (I failed this year at finding my goals there) but unfortuantely the sweet herps in the rivers are likely gone, but that is another story. Back to fish. Blackside Darters will hardly ever perch on the bottom and scoot around as a typical darter. They swim up with the minnows and hover like little harriers (the birds or the planes). An awesome fish and quite common in Ohio. Logperch are capable of sustained swimming of the bottom but are more likely to rest on the bottom, especially in the day. But you are right that most darters do not sustain swimming in the water column but all can swim in the column, at least for a little while, with or without current.

If you ever want to get out and start really learning your fishes really just let me know.

Andy

Edited by andyavram, 11 August 2010 - 03:13 PM.

Darters in the genus Percina will swim about in the water column much more than Etheostoma.

Edit - that's what I get for starting a reply and walking away from the computer for a minute. Andy's post is right on.

One of my logperch jumped out of the tank at feeding time a couple days ago. It got quite a bit of air, too! Luckily it landed in the tank next door, so it didn't get hurt. I guess it was excited about supper.

One of my logperch jumped out of the tank at feeding time a couple days ago. It got quite a bit of air, too! Luckily it landed in the tank next door, so it didn't get hurt. I guess it was excited about supper.

My fish have done that a couple of times, but with less hilarious results. I lost this really awesome natural mutation spotted black shiny swordtail that way. She was the only black swordtail I've ever seen with those black shiny scales on some of her body and clear areas on other parts. Found her behind the tank all dried up and shriveled one day.
And ghost shrimp kept in a tank without live plants seem to jump out at the rate of one a day. Eventually I got so fed up that I used three inch wide packing tape (two strips of it taped back to back to one another to make a non-adhesive line) to cover the holes in the top of the tank and leave them no possible way to escape. Stupid shrimp.

I think it's important that every tank be designed to be fish-escape-proof. I can't believe the people who advise others to design their tank around the 'suspended light' design (image: http://www.aquariums...aquarium_sm.jpg ) when they could very well rest the light on the tank top, getting the same lighting results and preventing fishy escape. Image: http://bp2.blogger.c.../fish-tank6.JPG

So I guess my point is this to the person who started this topic and is designing a tank: create a design so that fish can't physically jump out of the tank. Because if you don't, they will, and you'll be sad.

Edited by Okiimiru, 12 August 2010 - 07:46 AM.

My fish have done that a couple of times, but with less hilarious results. I lost this really awesome natural mutation spotted black shiny swordtail that way. She was the only black swordtail I've ever seen with those black shiny scales on some of her body and clear areas on other parts. Found her behind the tank all dried up and shriveled one day.
And ghost shrimp kept in a tank without live plants seem to jump out at the rate of one a day. Eventually I got so fed up that I used three inch wide packing tape (two strips of it taped back to back to one another to make a non-adhesive line) to cover the holes in the top of the tank and leave them no possible way to escape. Stupid shrimp.

I think it's important that every tank be designed to be fish-escape-proof. I can't believe the people who advise others to design their tank around the 'suspended light' design (image: http://www.aquariums...aquarium_sm.jpg ) when they could very well rest the light on the tank top, getting the same lighting results and preventing fishy escape. Image: http://bp2.blogger.c.../fish-tank6.JPG

So I guess my point is this to the person who started this topic and is designing a tank: create a design so that fish can't physically jump out of the tank. Because if you don't, they will, and you'll be sad.

Fish jump, it's inevitable. If you don't cover the tank, you lose them.

Those open-top designs usually contain a small number of cheap fish, which I assume simply get replaced fairly often. For those of us who actually like our fish and don't just have $1.99 tetras...well, you have to cover the tank.

Fish jump, it's inevitable. If you don't cover the tank, you lose them.

Those open-top designs usually contain a small number of cheap fish, which I assume simply get replaced fairly often. For those of us who actually like our fish and don't just have $1.99 tetras...well, you have to cover the tank.

Or put up a fence. I have an open topped tank with a suspended light over it. My Dad built me a sort of fence out of PVC "lumber". It's seven inches tall and just sits on top of the tank. I have lost a couple of dace, but I learned to cover it for the first couple of weeks I bring dace home. After that, they are settled in and don't jump out any more. Someday I'd like to replace it with clear acrylic. I think that would look nicer. I'll make it a little taller, too. I have plants growing out the top of it. I really like it.

Or put up a fence. I have an open topped tank with a suspended light over it. My Dad built me a sort of fence out of PVC "lumber". It's seven inches tall and just sits on top of the tank. I have lost a couple of dace, but I learned to cover it for the first couple of weeks I bring dace home. After that, they are settled in and don't jump out any more. Someday I'd like to replace it with clear acrylic. I think that would look nicer. I'll make it a little taller, too. I have plants growing out the top of it. I really like it.

Do you have a picture of that fence? It sounds cool.

Thanks for the responses, guys.

At this point, I think I'm going to wait on the darter tank until I move to a cooler location. I don't like keeping fish if they're unlikely to appreciate the conditions, and summers can be pretty bad here.

Instead, I think I'll set up a Central Mudminnow (Umbra limi) biotope - those guys should have no problem dealing with 80 degrees at the peak of summer.