What Causes My Water To Turn Green?

[oneshot]

I must be missing something.  Every tank I've ever had has eventually turned dark green.  What causes it?  Too much light, not enough water changes, water chemistry?  Any info would be appreciated.  I see tanks on youtube that are crystal clear.  Makes me give up on the hobby, only to try again in a year or so with the same results. 
ETA:  I don't even have tank lights, just room lights and two windows across the room

 

[jag51186]

Is the water green?? If so it is usually caused from a poor maintenance schedule causing a buildup of nutrients/nitrates in the water, giving the algae something to feed on.
 
If the green is on the tank, it is probably same thing. All algae comes from too much nutrients available for algae to feed on...aka nitrates.

 

[StevenF]

 
 
What causes it?  Too much light, not enough water changes, water chemistry? 

All of those can cause algae growth.  Algae need light to live.  To much light can allow algae to take over the tank.  insufficient water changes can allow some nutrients to build up in the water while at the same depleting others causing the chemistry, water harness (GH) and total Alkalinity (KH) to change.   
 
When neutrients build up in the water it is commonly nitrogen, phosphorous, or potassium (Commonly referred to as NPK).  They are known as macro nutrients  Plants and Algae typically need a lot of these.  In addition to ammonia, nitrite, and nitrate you can also get a test kit for Phosphates.  In my experience high phosphate levels are a frequent cause of the problem.  All fish food added to a tank naturally contains NPK.  
 
The elements most likely to be depleted in an aquarium are the micro or trace nutrients.  Only small amounts of these neutrient are found in water and if they get depleted plants will typically have slow or no growth.  
 
due to hard tap water I have been using Reverse osmosis  (RO) water in my tank.  RO water is depleted  of all macro and micro nutrients. As a result my plants didn't do well and  typically died.  I was able to resolve that issue by adding micro nutrient to my RO water.   My plants did grow but so did algae.  In fact most of the time algae dominated all growth in my aquarium.  I eventually purchased a phosphate test kit.  I discovered my phosphate levels were very high 5ppm.  If i cycled water in my tank very frequently  and did a large water change I could get it under control for a while.  Plant growth was however still slow.  My nitrate levels in my tank were zero (depleted)  I then decided to add a nitrogen fertilizer to my tank.  If my plants did well the combination of nitrogen and micro fertilizer did sometimes result in a rapid drop in phosphate levels.  But plant growth was still inconsistent.  I recently switched to a more complete micro fertilizer (Seachem Flourish) with a potassium nitrate fertilizer (Seachem Nitrogen) and since then, about 4 months, my phosphate levles have consistently been below 0.5ppm and with the help of nerite snails and Amano Shrimp my aquarium (algae eaters)my tank is now clear of algae.    Basically I solved the problem by adding all nutrients except phosphate and then added algae eaters and hopped the plants would consume the phosphate faster than the algae.  It worked.

 

[Akasha72]

just to re-iterate what the others have said. We all have algae, it's inevitable part of the hobby. We combat it by having good tank maintenance systems and the addition of algae eaters - whether that be fish, snails or shrimps.
 
If algae growth is to the extreems the you need to consider what is out of balance (as Steven put far better than I can). I too have a phosphate problem and so I fight with black beard algae on a day to day basis. I've added a phosphate remover to my filter and I added specific fish that eat black beard algae to help me combat it from both angles.
 
Every fish tank is a delicate balance. If you are using tap water for your tank it's always best to know what is in that tap water and I'd always recommend running a full water test on their tap water aswell the tank water. In my case the phosphate is incredibly high in my tap water and so I have no hope of getting rid of it. I've had to find ways around it instead.

 

[twintanks]

Out of interest, is there a phosphate kit in the API range? I've got algae (but not too badly) and would like to test my water, for my own interest.

 

[NickAu]

You should try MTS. ( Malaysian Trumpet Snails ) personally I think every planted tank should have them.
 

 

Malaysian Trumpet Snail ​

Melanoides tuberculata​

 ​

By: Ryan Wood
The Malaysian Trumpet Snail is a great to have in any aquarium. There are some with different patterns, shapes, size, dark or light colored. It is a beautiful snail to see up close in person. In some forums as well as blogs the Malaysion Trumpet Snail is instead used as the acronym MTS.
There is a lot of bad rep that all snails have received. A lot of hobbyists tend to think that having any type of snail in their aquarium is horrible and all must be removed immediately. There are even chemicals that are solely meant for killing snails in the aquarium. I highly recommend that you never use any chemical meant to kill snails in a tank with shrimp. Snails are not bad for your aquarium. Overfeeding your tank is what causes snail outbreaks. Most snails will actually leave your plants alone and instead eat the algae off of the leaves as well as glass. Do not think that a snail is a pest, they can be extremely useful in any aquarium.
The Malaysian Trumpet Snail is actually a benefit to any aquarium for several reasons. It will not eat your plants at all. This snail also will not "muscle" your shrimp off of food meant for the shrimp. The Malaysian Trumpet Snail feeds on detritus and leftover food that is underneath the substrate. It actually burrows in the substrate and moves around throughout. You will rarely see this snail during the day. Occasionally it will emerge from the substrate. A cool thing is that sometimes you will see the substrate move and you will know that there is a Malaysian Trumpet Snail underneath doing its cleaning duties.
The fact that this snail burrows and eats detritus is an excellent perk to having it. Another great perk is that while it is underneath the substrate moving it is at the same time aerating the substrate. Substrate aeration is a great benefit to planted aquariums as it promotes air exchange and root growth. They will not disturbed any plant roots or move wood/rocks around your aquarium.
The Malaysian Trumpet Snail reproduces live young and does not lay eggs. They can reproduce rapidly however. Rapid reproduction is a sign that you either need to feed your inhabitants less or vacuum the gravel extensively. You do not want to rely on this snail to do all of the gravel cleaning. High temperatures can also result in rapid reproduction if coupled with overfeeding.
This snail is an all around must have for most aquariums. They are very cool to look at, extremely docile, do not eat plants, aerate substrate, eat detritus, and do not harm other inhabitants. I highly recommend this snail to anyone.
 
http/www.planetinverts.com/malaysian_trumpet_snail.html

 
 
Also this by Byron.

 
 
Substrate Bacteria

The greatest population of bacteria in a healthy balanced aquarium occurs in the substrate, not the filter. The floc or humic compost that collects in the substrate is the host for the biofilms; this is why the substrate in planted tanks should never be disturbed, and many aquarists apply this to non-planted tanks as well.

In very general terms, aerobic nitrification takes place in the top 1-2 inches of the substrate; anaerobic de-nitrification takes place approximately 2-4 inches down, and anaerobic bacteria producing hydrogen sulfide occurs in substrates deeper than 3-4 inches. In all three cases, it will be deeper in coarse substrates (like pea gravel) and more shallow in finer substrates such as sand. These generalities will also vary with the presence of live plant roots and substrate “diggers” such as snails and worms, since these factors result in more oxygen being made available in the substrate, reducing anaerobic bacteria activity. An oxygen level in the substrate of as little as 1 ppm promotes nitrogen reduction rather than sulfur reduction (hydrogen sulfide). [6]

Maintaining a substrate of fine gravel or sand no deeper than 4 inches, having live plants rooted in the substrate, and keeping Malaysian Livebearing snails are the best and safest methods of providing a healthy biological system for aerobic and denitrifying anaerobic bacteria.
 
http/www.tropicalfishkeeping.com/member-submitted-articles/bacteria-freshwater-aquarium-74891/

 

[StevenF]

API does make kit (I have it).  However the color difference from 1.0 0.5 to 0.25 and 0 is very subtle which can make it difficult to precisely determine the amount in the tank.  unfortunately it is the only kit I have tried so I don't know if there are any better kit available.

 

[Akasha72]

I have the JBL po4 kit. It's very good. It ranges from pale blue to almost black. If the test is pale blue all's well, if it's nearly black you've got a problem

 

[Byron]

I must be missing something.  Every tank I've ever had has eventually turned dark green.  What causes it?  Too much light, not enough water changes, water chemistry?  Any info would be appreciated.  I see tanks on youtube that are crystal clear.  Makes me give up on the hobby, only to try again in a year or so with the same results. 
ETA:  I don't even have tank lights, just room lights and two windows across the room

 
I think we need more data.  I will assume you do not have live plants (without tank lighting this is next to impossible unless the tank is directly in front of a window with fairly bright light), therefore all the nutrients that naturally occur from feeding the fish will be available for some form of algae.  As someone noted, this is just nature.
 
Water changes are crucial to maintaining a balance, and we need to know the frequency and volume, if they are being done.  And what is the fish load (species and numbers, and tank size)?
 
Also, is the green on the glass (the aquarium glass needs regular cleaning, usually every water change, at least the front glass) or is the water itself green if you remove a glass of water from the tank?
 
What are the water parameters (GH, pH, temperature) and what are the numbers for nitrates?
 
Byron.

 

[oneshot]

I'll get some numbers together, but the water turns green, not just algae on the glass.  The load is nothing really, 2 guppies and one crayfish.  It's a 65 gallon tank.  No live plants.

 

[Byron]

I'll get some numbers together, but the water turns green, not just algae on the glass.  The load is nothing really, 2 guppies and one crayfish.  It's a 65 gallon tank.  No live plants.

 
Test the tap water alone for nitrates, as well as the tank water.  This is important.  You didn't respond to my question about water changes, how often and how much?

 

[vwdank]

I got my API phosphate test kit in today and as suspected my phosphates are very high in my 55 gal 5-10ppm 10ppm at least. This is the same tank with high nitrates although I have gotten nitrates down to 10-20ppm.  Tap water is 0-0.2 for phosphates
 
First question I have is what is the best phosphate remover? I have been reading up on PhosBan but wanted to ask the forum first. Edit: now i am wondering Phosban or Phosgaurd?
 
I mention before this is the tank that I only had under gravel filtration with 550 powerheads only and lets just say i did not follow tank maintenance like I should have.
 
I have added a Fluval external filter about a month ago and have been doing 40% weekly water changes since the 75% water change over a month ago.
 
I am sure I need to remove the under gravel filters and clean the gravel but i am worried about releasing even more toxins in the tank. Any suggestions on the best way to tackle this would be appreciated. 
 
I have been looking at canister filters primarily Cascade 1000 and EHEIM 2215. Casacade is lower in cost seems more user friendly but EHEIM seems to be better quality(only because its been around longer from what i have read) also EHIEM wins the quit battle if by just barely, these are from the numerous reviews i have read. ether way i will be making my purchase tomorrow and will most likely go Cascade as money is tight.  

 

[Byron]

I got my API phosphate test kit in today and as suspected my phosphates are very high in my 55 gal 5-10ppm 10ppm at least. This is the same tank with high nitrates although I have gotten nitrates down to 10-20ppm.  Tap water is 0-0.2 for phosphates
 
First question I have is what is the best phosphate remover? I have been reading up on PhosBan but wanted to ask the forum first. Edit: now i am wondering Phosban or Phosgaurd?
 
I mention before this is the tank that I only had under gravel filtration with 550 powerheads only and lets just say i did not follow tank maintenance like I should have.
 
I have added a Fluval external filter about a month ago and have been doing 40% weekly water changes since the 75% water change over a month ago.
 
I am sure I need to remove the under gravel filters and clean the gravel but i am worried about releasing even more toxins in the tank. Any suggestions on the best way to tackle this would be appreciated. 
 
I have been looking at canister filters primarily Cascade 1000 and EHEIM 2215. Casacade is lower in cost seems more user friendly but EHEIM seems to be better quality(only because its been around longer from what i have read) also EHIEM wins the quit battle if by just barely, these are from the numerous reviews i have read. ether way i will be making my purchase tomorrow and will most likely go Cascade as money is tight.  

 
Here it is clear that the phosphates are occurring within the aquarium, and that can easily be handled without resorting to chemicals or special filtration.  Phosphates high in the tap water are a very different problem.
 
Regular partial water changes, not overstocking, proper stocking (species and numbers), substrate cleaning to some degree, and not overfeeding (phosphates sufficient for plant growth will enter the system from the fish foods alone)--these practices should keep nitrates and phosphates in check naturally.  Once you get things back in balance, this should not be an issue.
 
I would also suggest tearing the tank down to remove the UG filter, if you decide not to use it.  There is no other way to handle this if you decide not to keep it running.
 
Eheim are good filters, and have the track record to prove it.  I have Eheim canisters, and an Eheim Mini in a smaller tank.  I also have a Rena XP3 Filstar on one tank, but prefer the Eheim.  I know nothing about the Cascade, so will leave that for those who do to comment.  But the reliability of Eheim is a significant factor; I have two that have been in operation since 1996 and 1998 respectively, with never an issue.  One has the heating element, which avoids tank heaters and I really like this feature.  More cost up front, but if it lasts for decades, well worth it.
 
Byron.

 

[StevenF]

Some phosphate removers are iron based.  Others are aluminum based Both will work.   I don't think you will see a big difference between brands.  I used Kent Marine phosphate remove to get my phosphates down.  However eventually I got my plants to grow  fast enough to keep it under control.  If I keep it below 0.5ppm i don't have algae issues.