Green fish tank...

Sarah1971

My fish tank (6 months old) started looking a bit murkier than normal so I decided to give it a good cleaning out. Spent 2 hours cleaning everything including the filter and the pump, and then I put my 4 little goldfish back in. This was only on Saturday, I got up this morning and I cannot see the fish, the water has turned almost a lime green colour!

I'm worried that the fish are going to die!
Is there anything I can buy to pop in the water to sort out this problem?

thanks

chatta

Is it by a window? To much light is the reason why it would turn green. Try to only change half the water, fish dont like chlorine much. Yes you can buy stuff to kill natural growing algea but moving tank away from direct light would save money and stress to you and fish Changing all the water etc, causes all sorts of strange things to happen If you feel urge to change water try and leave filter alone it will contain very good bacteria that helps to keep water clean. Rinse any debris out but no more than that.

Sarah1971

No the tank is in a dark part of my kitchen with just the artificial tank light on it. I knew I shouldn't have emptied all the water out! Doh!

Do you think it will settle down in a few days?

bunking_off

You do occasionally get algae bloom in a new tank...and regretably by doing a 100% water change you've defacto got a new tank. If you've put water in there without dechlorinating and washed the filter under the tap, chances are you've killed the bacteria in the filter and that'll take some time to re-establish. Your fish may survive (always worth hoping, and presence of algae is generally a sign of excess oxygen/light), but I wouldn't get your hopes up : experienced keepers apparently use "sacrificial" fish at this stage to get the filter up and running (the biological cycle is triggered by cr*p from the fish being converted to more harmless stuff...see this.

It's probably worth leaving the artificial light off for a few days and adding a chemical algae killer : any aquarium shop will have these.

In future;

- clean your tank regularly (weekly/fortnightly) with the fish in situ rather than one mad session.
- change 10-20% of the water. Use the water you take out to gently rinse the filter...never clean the filter with tapwater as it'll kill the bacteria in it.
- replenish the water with water that's been treated with dechlorinator (again, local fish-shop). In theory you can by-pass this by using water that's been left in a bucket for a couple of days to evaporate the chlorine off, but I've never really trusted this for the sake of dechlorinator that costs a fiver and lasts for years.

Hope your fishies survive...if not, don't beat yourself up about it, mistakes are how we learn.

alanobrien

The problem with algea is they take up all the oxygen
which can cause fish stress which leads to disease and worse.

If you have a filter pump make sure its running constantly and make sure their is movement at the surface of the water this is where the oxygen exchange takes place.

In a new system the fish poo turns radidly to ammonia, then
nitrite both of which are toxic then finally into nitrate which isnt - at least in small doses. so small regular water changes will be necessary.

As someone once said "The answer to pollution is dilution"
no idea who but its snappy.

More info here;
http://faq.thekrib.com/begin-cycling.html

scheming_gypsy

stick a couple of plec in, they'll have the algae eaten away in no time.

JennyW_2

chatta wrote:

Is it by a window? To much light is the reason why it would turn green. Try to only change half the water, fish dont like chlorine much. Yes you can buy stuff to kill natural growing algea but moving tank away from direct light would save money and stress to you and fish Changing all the water etc, causes all sorts of strange things to happen If you feel urge to change water try and leave filter alone it will contain very good bacteria that helps to keep water clean. Rinse any debris out but no more than that.

you will have done more harm than good by removing all the water and scrubbing everything - you will have killed all the good bacteria. You may find that you will need to buy a more efficient filtration system. I've kept tropical and marines and never had a problem with green water. It's the filtration system which keeps the water crystal clear. Are you also treating your tap water before putting it in the tank?

Bossyboots

Agree with everything that has been said. We have just reestablished our tank after losing our last fish to what we now realise was the use of a non aquariam friendly air freshner. We haven't needed to sacrifice any fish and a good fish keeper shouldn't. Provided all is set up properly and the correct preparations used, you can put fish in and they will survive while the filter gets going.

When we were kids, we had goldfish and we always emptied the tank every few months and there was no messing about with filters and the like and we kept fish very successfully (as long as we remembered to keep the lid on so that cat couldn't get them). Our aquatic centre say that it is the quality of our water these days that makes all the paraphenalia necessary now.

To the OP - you need to take some advice on your tank and fish from an expert and if you want them to survive you may need to treat the tank with medicine and anti-stress preparations. Our local centre will take fish in and look after them if you have a tank disaster to give you a chance to sort things out. It might be worth asking if you have somewhere local that might do this.

bunking_off

I've kept tropical and marines and never had a problem with green water.

Would agree with that. The only time I've ever had green water was when I set my very first tank up, and it cleared in time. Since then, when I've set up subsequent tanks I've always got them started with water from an established tank. The OP regrettably got rid of all her water so defacto had a new tank, hence the bloom. It won't happen everywhere, very much depends on the quality of the water being supplied which does vary regionally.

We haven't needed to sacrifice any fish and a good fish keeper shouldn't.

Oh, agree totally. Re-reading my earlier post I should have said "some" experienced fishkeepers use that technique. It isn't one that I've used myself. I do, however, pick hardy species when establishing a new tank.

Interesting comment about water quality deteriorating. With hindsight it always intrigued me how any of the goldfish that we had as kids survived being plunged into tapwater without any thought of quality/temperature etc. I'd have a slightly different take on the quality though : I think with our nanny state, the companies bung a lot more chlorine etc in than they used to and that makes the difference. Having said that, I know from testing that there's a fair bit of nitrate in our tap water - certainly more than the manuals say we should be aiming for in our "clean" tank.

JennyW_2

bunking_off wrote:

I do, however, pick hardy species when establishing a new tank.

We were always recommended black mollies to establish a tank. They tolerate both fresh and salty water and hardier than most fish. But unfortunately you will always lose fish when setting up a tank due to high nitrite and ammonia levels

From memory, I believe it takes about 6 weeks to establish

chatta

I believe the tank contains goldfish, which are coldwater fish. People are recommending tropical fish, none of which will enjoy a non-heated tank :eek: