Flashing

[Dutch]

I have a problem in my tank and I can't seem to identify what the reason might be. My fish are flashing. At first I saw only the Danios that did it, but recently I've seen the same behavior with the kubs. They don't do it often, just every once in a while, but I still have the impression the fish are somewhat stressed.
I've treated for parasites, but that doesn't seem to have done anything.
This has been going on for around two months and it doesn't seem to affect the fish much. No white spots or such, they eat well, grow well and are out and about.
Does anyone have an idea what it could be?

The tank is a 100 gallon with internal filter (8 gallon) and houses 27 D. kyathit, 7 B. kubotai, 1 A. botia and 3 C. siamensis.
Water has been checked regularly and always showed very low levels of nitrate etc. There is some blue-green algae in the tank, but I keep cleaning it. I change about 30% water a week.
There are plants in the tank, but they are not in optimal condition as they get covered by brown algae all the time.

[newshound]

brown algae...low light?
loaches do flash...it is like scratching yourself.
but I'd do a 50% WC (slowly adding the new water).

[andre]

Dutch does if happen after feeding time and they do it on the sand?

Often it is a way to lift food debris from the ground.

I often observe that and never had any disease of any kind. Just keep an eye on that but don't panic

[Dutch]

Thanks!
I have three 38W T8 lights on for about 11 hours a day and the brown algae are on the Vallisneria leaves towards the top of the plants. I don't understand it either.

I have had weeks with 50% water changes, but it doesn't seem to make any difference.

Andre might have a point, it does seem to happen more with the kubs during feeding time.
The Danios seem to do it most when I do some work in the tank. I sometimes think it might be a stress response they show. plus, only a few Danios do it at the same time. I have 27 and only see two or three doing this.

[san-ho-zay]

I have three 38W T8 lights on for about 11 hours a day and the brown algae are on the Vallisneria leaves towards the top of the plants. I don't understand it either.

Are you feeding the plants?

[chefkeith]

This is in a river tank or with high water flow?

Do they flash when the water current is with them or against them? In my river tank when the loaches swim with the current I'll see them flash often. When the water flows from their back to the front of the fish it may irritate their scales and gills.

When my loaches are relaxed and standing still they are always facing the same direction against the water flow. Usually the only time they flash is when they turn around in the water flow.

[Bully]

My B. striata seem to use flashing in their displays of hierarchy.

Brown algae is common on new setups and sometimes takes months to settle; cyanobacter can occur in areas of low or poor water flow.

You can check out the following website for a brief guide to the common algaes:

http://mralgae.blogspot.com/2008/02/algae-guide.html

[Diana]

38 w X 3 bulbs over a 100 gallon tank is very low light, as far as the plants are concerned. Brown algae (Diatoms) will eventually go away.

[Dutch]

Are you feeding the plants?

No. I used to give EasyCarbo (liquid CO2 replacement) and Profito (fertilizer) but I quit using that because I didn't trust those as far as their effect on the fishes health. Plus, my intention from the start was to create a tank that would only require me to use tapwater (which is of good quality). I know the nutrients are low, but it's very expensive to add all the stuff for plants and I simply don't trust it for the fish.

This is in a river tank or with high water flow?

Do they flash when the water current is with them or against them? In my river tank when the loaches swim with the current I'll see them flash often. When the water flows from their back to the front of the fish it may irritate their scales and gills.

When my loaches are relaxed and standing still they are always facing the same direction against the water flow. Usually the only time they flash is when they turn around in the water flow.

Yes, the water is flowing fast, but the flashing doesn't seem to happen in a specific situation.

btw. Just out of interest. Why would you think the current from back to front would irritate their scales?

My B. striata seem to use flashing in their displays of hierarchy.

Brown algae is common on new setups and sometimes takes months to settle; cyanobacter can occur in areas of low or poor water flow.

You can check out the following website for a brief guide to the common algaes:

http://mralgae.blogspot.com/2008/02/algae-guide.html

Thanks for the link.
So far I've only seen my kubs flash when they are by themselves. For the hierarchy they just chase each other. Seen them grey out only once so far. Which is interesting because in the shop they were constantly greying out.

38 w X 3 bulbs over a 100 gallon tank is very low light, as far as the plants are concerned. Brown algae (Diatoms) will eventually go away.

They aren't bulbs, but TL lights (with reflectors). It should be enough for good plant growth. I even switched two lights a few weeks ago. There's now two Sera daylight (6000 Kelvin) and one tropical sun (4700 Kelvin) ( http://www.sera.de/index.php?id=63&L=1 ). I can only go higher with a 12000 Kelvin blue sky.

[Dutch]

Just to show what the tank looks like for those who haven't seen it.

[san-ho-zay]

Are you feeding the plants?

No. I used to give EasyCarbo (liquid CO2 replacement) and Profito (fertilizer) but I quit using that because I didn't trust those as far as their effect on the fishes health. Plus, my intention from the start was to create a tank that would only require me to use tapwater (which is of good quality). I know the nutrients are low, but it's very expensive to add all the stuff for plants and I simply don't trust it for the fish.

I understand your concern but healthy plants are a great benefit to fish in themselves. If there is a lack of nutrients, the plants will have a tendency to abandon leaves to die. These leaves will secrete small quantities of ammonium (too small to harm your fish BTW) which is reckoned these days to be one of the major algae triggers. Aside from being ugly, some types of algae also consume significant oxygen.

You are lightly to moderately planted, not dosing carbon and I think you are suggesting your light levels are low so it's not a case of going mad and dosing lots of ferts. But I think continuing a minimum dose of a good basic trace food with iron, magnesium, etc. plus potassium (like Profito) is a good idea to ensure that the plants can function. As long as you don't have the lights on for more than 10 hours/day, you probably have enough nitrate and phosphate from your livestock/fish food.

The brown algae you've got now should come and go but I don't want you to get the same sort of algae problems I did because you've abandoned feeding. I got lazy with ferts in my main tank and had a couple of nasty algae outbreaks that have involved lots of hard pruning. It's growing back in now and, touch wood, with the help of regular fertilization of the plants, little or no algae.

This photo illustrates the problems I've had and the turnaround I'm seeing by using the right plant food.

[Botia Robert]

I have noticed this flashing too.

Loaches (Kubs) do like to plough head first into the substrate so they may need to shake off something.

Regarding the algea, would some Ottos or Plecos or SAEs help?

[chefkeith]

This is in a river tank or with high water flow?

Do they flash when the water current is with them or against them? In my river tank when the loaches swim with the current I'll see them flash often. When the water flows from their back to the front of the fish it may irritate their scales and gills.

When my loaches are relaxed and standing still they are always facing the same direction against the water flow. Usually the only time they flash is when they turn around in the water flow.

Yes, the water is flowing fast, but the flashing doesn't seem to happen in a specific situation.

btw. Just out of interest. Why would you think the current from back to front would irritate their scales?

It's just a theory from my observations and experience.
It's when the water or anything else goes against the grain of their body. Their slime coat and scale pattern adds a layer of protection, but if the something is rubbing the wrong way against their scales it probably feels like a bug is crawling on them. Now I'm getting itchy just talking about it.

To put it another way, loaches have no problem getting into tight hidey holes head first, but they may have problems getting out of holes going backwards. That's because there is more friction going back to front than there is from front to back.
Another example, is if you ever held a fish in your hands you'd know how slippery they are when you hold them tail up, head down. But if you hold them head up, tail down they won't slip through your hands as easily because of the friction from the scales.
( I know this from handling fish when I was a chef. Obviously, I wouldn't do this with my pet fish.)

[Tinman]

You should add a UV sterilizer Dutch. I remember when you set this up it took some time to clear,is all the tank water passing over filter or was some bypassing? Flashing could be parasites or water conditions imo,fish will swim close to the gravel to thrust food up but scratching is an irritant. Is your water naturaly hard? One of those new rocks could be the culprit as after a few months they start leaching, a bucket test on some rocks is in order? Are any rocks rusting? Check your heater....

[Dutch]

San-ho-zay, I've actually looked at the Profito again and decided to start adding in in low doses again. It's some Fe, Mn and K and such and should be okay for the fish. So maybe it will help the plants.
I don't add EasyCarbo because I simply don't know what's in it.

Robert, I have three SAE since about two weeks and they grow really fast, so I guess their contribution will show in a few weeks time.

Tinman, it did take a long time for the water to clear, but the filter works perfect now. I have a lot of flow and all the water passes over the filter. The water here is naturally soft and the stones I have all come from rivers and are commonly used in aquaria. I had one rusting rock, but that never went in the tank. Temperature is also fine. I do agree that there might be some irritant in the water, but I can't identify it.