I REALLY NEED HELP PLEASE My fish tank has algae in it which im ok will but now Im seeing black algae? Mold?

There's a good chance that all you're seeing is additional algae, which may just be of another type.

DON'T add algae killer to the tank. While this may sound like a good idea, it isn't. When the algae dies, it produces ammonia and other componds that are toxic to your fish. A little may not have been a problem, but if your tank has a lot of algae, it may be more than your fish can survive if it all dies at once. It also doesn't address why you have algae, and this may be the reason your fish look sick.

The fish also produce ammonia as a part of their wastes, and this is usuallt converted first to nitrite (which is also toxic) then to nitrate (less harmful as long as the concentration isn't too high) by bacteria in the tank. Although the ammonia and nitrite get changed by the bacteria, nothing "changes" the nitrate, so it builds up in your tank until you remove it by doing water changes. Nitrate itself is a plant (and algae!) fertilizer, so this, combined with good lighting, is what allows the algae to grow. And even though nitrate is safer for your fish, if the level rises too high, it can kill them.

What I would advise you do to is to use a scraper to remove as much algae as you can from your glass, and an old toothbrush for rocks and ornaments. Then use a gravel vacuum to siphon all this out of the tank, as well as cleaning down into the gravel to get any debris that may have accumulated there. Don't remove more than 1/2 of the water when you clean, so this may take you 2-3 days, changing no more than 50% of the water each time, to clean your tank. But this will lower the nitrate level considerably and will help with the health of your fish. When you add the replacement water, do so slowly! Make sure it's about the same temperature as what's in the tank, and that you add conditioner to remove any chlorine/chloramine that your water company adds if you're on a public water supply.

Following the first cleaning, leave any lights on the tank off (as long as there's some light in the room so your fish can see to eat) and leave them off for a week. And be sure you aren't overfeeding your fish - they should only get what they can finish eating in 2-3 minutes, twice a day (although you should feed the algae eater at night, since these are nocturnal - if there's any food left in the morning, remove it). After about 2-3 large water changes, switch to 25% changes once a week to keep the nitrate levels down.

You may also want to contact your water supplier or get your water tested for nitrate and phosphate (another "fertilizer"). If these are present in your water supply, you'll always be adding more "fertilizer" to your tank every time you do a water change. You may need to resort to special resins made to remove these, or switch to reverse osmosis water to keep the levels down. And if you don't have one, a water testing kit is a good idea as it allows you to check your own water chemistry (unless you have a pet store nearby who will do this for you).

There's also a possibility that what you have isn't algae, but cycanobacteria which looks similar, but is usually a brighter green: http://www.aquamax.de/Shop/Artikelbilder/Zusatzbil... Controlling the nutrient levels is still your best method of control.

I'll put some additional info for you on both of these below:

There are many kinds of algae. While they generally aren't bad for the fish, they certaintly don't look that great on your tank. How long are you keeping your lights on? Does your tank get direct sun light? Light is essential for algae to grow, but as long the fish can see enough to eat, they don't need it. Which means, as long as your room is lit enough you can keep your tank lights off most of the time to cut down on algae. Your bottom feeder, if he is a algae eater like the Pleco, or Chinese Algae Eater will not be happy with a change from green algae to black algae. Green algae is the one they prefer/ will probably eat. Make sure they are getting algae wafers if this is the case. And make sure to keep up on your water changes!!!!

There are a lot of different kinds of algae like red, brown, black, green, green hair, etc. Also there are different kinds of bottom feeders, some eat mainly algae and others eat mainly left-over food.

If you only have one small little algae eater in a big 55 gallon tank (this is an example), it can't clean the whole area itself. So make sure you have enough algae eaters in your tank.

It's just algae it won't hurt the fish. Why is everyone so scared of Mold these days???

You should clean your tank and change about 25% of the water about every 3 weeks. This will cut down on ugly algae growth and also keep amonia (fish poo) levels down. The fish will thank you for it.

This is very heathy algea and your fish will be fine. To reduce the amount of this you need to wipe your glass down every few days, reduce the amount of time you leave your light on, make sure your tank is not by a window, and make sure the temperature doesn't get too much over like 76 degrees f. If you do all this your problem will reduce significantly.

Get some of that algae killer. I use it regularly, about once a month. In about 2-3 days use some crystal clear to clump up all the floating debree. A good site to look at is fishlure.com. Open the window for tropicals and you'll be amazed at what you can find out.

remove the sick fish and isolate him until you get this under wraps. Do a water change immediately! Gas bubbles from something like that can not be good. check your filter and change it just in case there are any of the "mouldy" particles in there that are getting back into the tank. take the water in to be tested, or test the chems yourself. scrub the sides before you do the water change to get the gunk off, change your filter so the gunk filters out and add new water. hopefully this helps.

need to put fish in bowl and clean tank...then use algae destroyer before it gets that bad...over feeding fish??? it will get some algae..change out half the water every so often...seems to help

u need to go get a sucker fish at pet store that will clean it all up that's what they eat is algae and every thing else that's nasty in their

sounds like black mold, you need to clean the tank