I can't get the tank clean!

[colesea]

But UV light is filtered out by glass and plastics.....? ???

Plastic splash guards and glass versitops would prevent UV light from entering the tank at all, thus protecting bacteria in the tank. The reason UV sterilizers work is because the water is actually in contact with the bulb (or at least in contact with a sleeve that allows the transmission and focusing of UV light, I think quartz is used), and the fact that the wavelength of the light is specifically tuned to be the most devistating.

Reptiles kept in tanks that have their full spectrum bulbs over glass tops suffer Vitamin D deficiencies because they are not getting the UVB they need from natural spectrum light for the production of Vitamin D.  That's why it is reccommened that full spectrum bulb be suspended over wire mesh tops (thermoregulation reasons we won't get into here).

Try it yourself.  Lay out on the floor in a sun-spot that is passing through your window glass. Stay there all day. Observe if you get a sunburn.  Then go outside and lay out in the sun all day. Observe if you get a sunburn.  
~~Colesea

 

[ronrca]

The definiation of Ultraviolet light (UV) is invisible light that causes phosphorous materials to fluoresce and produce visible light (UV-A), causes skin to redden (tanning UV-A and UV-B) and causes certain bacteria to be destroyed (irradiation UV-C).

We know from science courses that light uses wavelengths and is divided into a spectrum. This spectrum is called the radiant energy (electromagnetic) spectrum. Of couse this does not only include visible light but everything from radio frequencies to UV, x-rays, gamma and cosmic rays. Visible light falls into 380-770nanometers.

Given that, electromagnetic radiation in the wavelength range between 180 and 700nm is capable of killing many species of bacteria, molds, yeasts and viruses.

It is true that glass and plastics block UV however only certain wavelengths depending on the glass and plastic, the thickness, distance from the light source etc. Regular glass, the kind used in aquariums and were used in older homes, do not block all UV therefore allowing some UV through the glass and into the water. The water will also block UV but how much? Specially when we talk about planted tanks that have a lot of light. You can be quite sure that some UV will make it through.

In the case of reptiles that suffer Vitamin D deficiencies, that is most likely because that wavelength is being block by the glass however like mentioned before, there are many wavelengths and not all are blocked by the glass.

Try it yourself.  Lay out on the floor in a sun-spot that is passing through your window glass. Stay there all day. Observe if you get a sunburn.  Then go outside and lay out in the sun all day. Observe if you get a sunburn

Most windows made today are made not just with 'regular' glass but also with argon gas and low-e gas. Some windows even keep out UV completly because of the construction, not because of glass. How many times have you heard of people saying that their carpet is 'bleaching' out where the sun always shines in or in your car (dashboards and so on). I know a girl that actually got a sun burn while driving. She did not have her windows open because she had the air conditioning on and she still got a sun burn (car windows are not made the same as house windows).

The reason UV sterilizers work is because the water is actually in contact with the bulb (or at least in contact with a sleeve that allows the transmission and focusing of UV light, I think quartz is used), and the fact that the wavelength of the light is specifically tuned to be the most devistating

Actually, UV filters work by having the water pass through the light given off by the bulb. The water does not have to make contact with the bulb. It is true that the wavelength produced is specially for killing bacteria (around 250nm). Light can travel through objects depending on the wavelength specially through glass. Just imagine how dangerous x-rays are (around 1nm).

I hope that helps and gives a better understanding about light and UV. Im still looking for the article about bacteria in the aquarium.

 

[colesea]

Ahhh...this is a perfect example of how a little knowledge goes all wrong.  I understood the various wavelengths of light and all part, but didn't know there were differnt kinds of glass! At least, I wasn't thinking logically enough to figure that out for myself *sheepish grin*. Glass is glass is glass, but apparently not. Then again...a kiss is but a kiss, a sigh is but a sigh...
~~Colesea *high on way too much learning tonight*

 

[equinom]

My son & I are new to this hobby, and were pleased to find an informative and helpful site.
We also have a cloudy water problem, have tried many of these suggestions - and it's getting worse.
We have a eclipse hex 5 and a 12.  The 5 was set up - complete with fish - in a couple of hours.  Didn't know to check temp or pH - just remove chlorine.  It went through the "new tank" stage, a little cloudy, but that cleared up after first complete maintenance.  Now that tank is crystal clear with happy fish.
As far as the eclipse 12 - that one was set up for 1 week before fish were introduced.  Had everything cleaned, installed, adjusted for temp & pH and let it run.  Added several small fish and let it run for another week.  That's when it started to get a little cloudy - white cloudy.  Got a few more small fish and added them - plus several srops of "crystal clear".  24 hours later and water is more cloudy than ever.  It could be my imagination, but it also looks like it's starting to yellow too.
The filter looks great - almost new in appearence.  The Biowheel is spinning fine - is it that it's not bacteria coated enough?  Please help!
We haven't lost any fish yet - but my small son keeps looking at the tank and saying he feels sorry for the fish in the fog...

 

[ronrca]

Sounds like bacteria bloom. Not much you can do but wait it out and hope that you dont lose any fish. You can continue with the water changes but only water changes. Do not clean or replace the gravel and filter medias. The best way to avoid it is using the fishless cycle. You dont have to worry about fish dying because of ammonia or nitrite poisoning.

 

[equinom]

Being that I had added a few fish for a week, I thought that would take care of the bacteria.  I guess adding the next batch of fish was too much for the existing bacteria.

I did check the ammonia level, and it was 0.  I also have added a small amount of bacteria - to help the process along.  Anything else I can do?

 

[ronrca]

You can check the nitrites also just to be sure. About the addition of 'bacteria', did you use 'Cycle' or 'bacteria in a bottle'? Dont be fooled by this marketing scheme. Bacteria does not live in a bottle even if it is dormant. Actually, dormant bacteria, unless frozen only lives for a couple months I believe.

By adding only a few fish every couple of months will not affect the water cycle unless your tank is over stock or your gallon/fish ratio is quite high. If you have 2 2" fish in a 90G and add another 2 2" fish, there will not be great affect on the waste produced because of the large water mass.