Issues with My Mbu Tank

[pufferpuggirl]

Okay, this is sort of a dual problem post. I did a water change on my big tank today, the one that BeeBoo my Mbu is in.

First issue: I have recently starting using those 'Polyfilter' filter sponges in some of my tanks. When I removed the sponge from the filter today, during the water change, it came out very much red. When I looked at the list on the packaging, it said that red meant "aluminum". I'm concerned .... how would aluminum be getting into my tank, and is it harmful to my fish?

Also while I'm talking about the Polyfilter -- does anyone know how many times I can reuse it before it's no good? And am I correct in understanding that I can rinse it in tap water, or soak it in hydrogen peroxide to make it "clean" again? I am seeing some nice results since using it, and I like that it removes bad stuff .... but I would hate to have to put a new one in the tank each time I do a water change, as they are not cheap.

Second Issue: I have a hang-on filter on this tank (along with several other filters, including a large external) and guppy fry are always getting into this filter and so I've come to turn the filter upside down so the fry fall into the bucket, and then I dump the contents of the bucket back into the tank when I'm finished, so the fry can get back into the tank. Today I decided to pour everything in the bucket through a sifter, and sure enough 3 baby fish came out. I put them back into the tank and when I looked into the sifter I could see something else moving about. I removed it and put it into a small dish and got my magnifying glass out. This thing is strange looking. It's green, has a longish body with 3 pairs of legs, and 3 extensions out the back. You can definitely see the eyes, which are on the very ends of the head. I sort of think this is a dragonfly larvae ... but that's just a guess. Keep in mind that this tank is inside and I am in England. I don't see dragonflies very often and can't remember if I've seen any at all since I've been here.

Any guesses what this might be and does anyone think it's a danger to my fish and/or puffer?

Any and all help is greatly appreciated. Thank you.

[lesleyanndunn]

i havent a clue what you have found!

but you always end up with interesting critters!!!

lol, will be good to hear what it is!

[pufferpuggirl]

Well I don't think that "thing" looks very friendly and I am hoping it's just a one-off and not part of a bigger group inhabiting the tank.

[Hilly]

We do get dragonflies, I get them around my koi pond during the summer. I've had dragonfly larvae in my snail tank a while back and it systematically destroyed most of the population. Evil things but kinda impressive on their predatory behaviour at such a size.

[RTR]

Yes, the Polyfilter can be re-used several times after rinsing/cleaning - this does little or nothing for the GAC component of the unit, but that is a relatively trivial thing other than organics, the other materials will be refreshed somewhat by the processing. I am unsure of the actual usable life of the whole unit - it varies quite a bit with the water and what materials are captured and their concentration.

The aluminum seems strange to me also - I cannot see why it would be high enough to picked out by the Polyfilter. That seem very unusualt o me also. I don't know much about potential toxicity from Al, but the site given below and other similar ites may help you track down any risks:
http://www.pesticideinfo.org/Detail_Che ... Id=PC33881.

Can you screen the intakes sufficient to keep the guppies out of the filter?

Guppies have been used in feeding dragonfly larvae (if that is what the critter is) by hobbyists they are a handy size. have you seen dead bodies in the tank?

[pufferpuggirl]

Thanks RTR for bringing up the issue of aluminum in the tank. I thought that was very strange.
By dead bodies, do you mean other "larvae" or fish?
If you mean fish, yes actually, I found an adult guppy dead this morning, before the water change. And I've been fishing dead guppies out every week at least. The one that came out this morning looked healthy in every way, not deformed, and definitely not too old. I am beginning to suspect either the aluminum or the "green thing" having something to do with these deaths.
I'm now worried about my Mbu ... although at the moment seems fine.

Just an after thought -- I didn't see a listing for lead on the polyfilter package. Is it possible that what is being picked up is lead and not aluminum?

[Ohyouknow]

by what I'm seeing of "dragonfly larvae" they look more like a squatty bug, but a damsel fly :

http://4.bp.blogspot.com/_QRsMm-ibHHk/S ... G_1282.JPG

Is that what you saw?

[pufferpuggirl]

Yes, I'd say that's exactly what I seen. Thanks Ohyouknow, you're good.

*****************************
I've just done a little research on them and the are a nasty predator, but apparently they aren't as bad as dragonfly larvae. Some information says they will only take small fish and other sites said they will take out whatever they can catch. They have jaws that extend out and it sounds alot like those 'Alien' creatures from the film of the same name. Obviously I removed the one from my tank, but let's just hope that was the only one. I know that dragonflies are good, they eat mosquitoes, but I'm sorry, I don't want their larvae in my tank plucking off my fish. I've been finding alot of fish dead lately and been wondering what the issue was. And now thinking about it, I bet that damselfly had everything to do with my salivator puffer dying as well because he used to sit on the substrate and sleep and from what I've read that's when those larvae become active and hunt for prey. Nasty little buggers.

[lesleyanndunn]

wow what a weird creature to find in your tank
is it harmful in anyway?

[Flutter]

You have to remember too though that they really don't eat that much. Insects are extremely efficient, much more so than fish.

[pufferpuggirl]

That may be true, but what I'm thinking is, what if this larvae is attacking my fish, but not able to eat them? ... then the fish would have a wound that causes it's death. That would account for all the recent deaths in my tank, but the appearance of healthy fish. I don't think you would really be able to see, very easily anyway, a bite made by such a small insect.

[xrayjeeper83]

how would something like that end up in your tank?

[Pufferpunk]

I think Filbert would eat that thing.

[RTR]

The dragonfly larvae pierce the body and suck out blood/lymph/other juices (rather spider-like - they do not eat it, just the vital juices). They leave the body behind. That is how folks catch on to their presence, by the dead bodies. They rarely attack large (relative to them) fish, but small fish such as guppies or the fry of other fish are the right size for the larvae. I don't know the detail of the other larva ID'd, you might search on that one for its feeding technique.

The company info says that red indicates iron removal by the Polyfilter unless you have an alternate formulation. Iron is much more common in water supplies. You might want to recheck that package info.

[pufferpuggirl]

I am a bit surprised one of my bottom feeders didn't get it, but it wasn't very big, maybe half an inch and very thin. I took it and placed it outside in a tub of water I've got, surprised it was still alive after spending all night in a small dish of water.

Well I think I now know the reason for all the dead fish I've been coming across lately.

This is what my packaging says:
aqua to light blue: copper or copper salts
orange: iron
bright red: aluminum
bright yellow: ammonia, amines or solvents
dark brown: tannins/humic acid
light tan progressing to dark brown: organic wastes