Water Quality

[olivehydra]

Howdy folks,
A question perhaps for any turtophiles of fishy folk...... I have a problem with algae in a 4ft tank. The algae is not on the glass but rather in suspension. I have stripped the tank bare including all substrate. I monitor ph, chlorine, ammonia, nitrite and nitrate levels and all is good. I run an external canister filter with well established bio filter. I have recently swapped to NEC blacklights for UV and am wondering if they are too efficient?? No direct sunlight reaches the tank and all un-eaten food and feacal matter is removed within a few hours. I house two med elns (110mm carapace) and the tank holds 155 litres.
Any suggestions welcome, thanks.

 

[Rupes]

from my exprience, i think u are feeding them too much, how often do u feed???

and also i find that adding some sea-salt once a month keeps the tank keen... havent changed my water in ages, just added what has evaporated

 

[Rupes]

btw what colour is the suspended algae?

 

[olivehydra]

I have been under-feeding them if anything. The vet weighed them last and tells me they are at the lower end of size to weight ratio for wild specimens. They have since increased their food to every second / third day. The algae is green btw. Cheers.

 

[dpeica]

How long is the light on for?

 

[olivehydra]

How long is the light on for?

8 -10 hours per day. Been off for 3 days with no visible improvement though.
Cheers.

 

[dpeica]

Green water is usually caused by excess light..Leave the UV off for a few more days and see if it improves. If it doesn't I'd consider investing in a UV sterilizer.

Out of curiosity, how long has the tank been set up? And what are the ammonia, nitrite and nitrate readings?

Edit- Also, what wattage tubes are they? Probably the most likely reason for your green water..

 

[olivehydra]

Green water is usually caused by excess light..Leave the UV off for a few more days and see if it improves. If it doesn't I'd consider investing in a UV sterilizer.

Out of curiosity, how long has the tank been set up? And what are the ammonia, nitrite and nitrate readings?

Edit- Also, what wattage tubes are they? Probably the most likely reason for your green water..

Tank has been set up for years but I did change filter foams recently so bio filter may not be at optimum quite yet. Ammonia is at 0ppm, nitrite at 0 ppm and nitrate at 20 ppm. Ph is close to 7.5 - 8. The tubes are nec t 10 which I believe are 18 w?
Cheers.

 

[instar]

Try to keep Nitrate at a little less than 20 p.p.m if possible. Probably the light, everything else sounds good. if its long hairy stuff suspended in the water its almost definately too much light. cut down the photoperiod, or lose the blacklight, buy plant benificial flouro and buy more plants to uptake avail light, and get the turtles outdoors for reg sunlight instead.

OR.. keep on scooping algae!

 

[peterjohnson64]

Thanks for this thread Dorian. I had to clean out my tutle tank tonight. I know, I have that outdoo rthing and yes, it has mum and dad. But I still have one bub left and his tank has gone all green as well. I had thought about jus tgiving him natural sunlight instead of a UV light in th etank for the same reasons. But I would like to know how other people do this? I am not going to put him in with the adults because he will get eaten by something. can I jsut set up a big container of water in the back yeard and say - "in ya go" and then for how long.

I heard on my sydney wildlife course that 2 half hour sessions a week in natural sunlight was better than a UV tube. Do others agree with this. sorry to seem serious at 11pm on Saturday. I just need to know this stuff as well.

 

[africancichlidau]

OK so we don't like the look of the water. Do the turtles have thread algae growing on their carapace? Is there sufficient bacteria in their water? do you use "Cycle" or some similar bacteriological additive? What sort of anti-chlorination solution do you use when changing water? Is ther some sort of uv filtration?

 

[Leon]

Turtles produce quite an amount of organic waste, which is just fertiliser for algae. A nitrate level of 20 ppm is more than enough for algae to grow. Water changes are the easiest way to lower the nitrate level. However, you need to be sure, the nitrate level of your replacement water is lower than the nitrate level in the turtle tank. So, you should measure the nitrate level of this water first. If nitrate is lower, then you should do more frequent and/or larger water changes. If it's higher, you should search for an alternative water source (if possible).
Another thing is that a biological filter doesn't lower the nitrate level at all. In fact, it increases it. The bacteria in the bio filter break down the turtles' waste. The final product of this process is nitrate. It's best to remove all removable turtles' waste as soon as possible. This way it can't be broken down to nitrate.
The longer the light period and the higher the light intensity, the higher the growth rate of the algae. So, you could reduce the photoperiod and/or light intensity, but off course you shouldn't keep your turtles at other than optimal conditions.

Hope this helps.

 

[olivehydra]

Thanks for the suggestions folks.
Africa..... One turt does have algae on its carapace the other doesnt. I heard the green ones are more valuable? :wink: I seed the bio filter using "stress zyme" and condition the water changes using "stress coat". No uv filter is in place.
Leon I'm aware of the nitrogen cycle, but must admit to not testing nitrate levels of water changes Good point, I will do so.
The only conclusion I can come to is that the reptile specific fluros are inferior to the NEC blacklights, as has been the opinion of many turt fanciers.