Tank Won’t Stop Turning Green?

Just a short little question, my tank has been fine forever and I recently added co2 according to my plants, I dose nutrients and use a Nicrew led light eight hours a day. I started doing water changes daily for a week, then I noticed the day after each change it just kept getting worse. I read a ton on this, but I still have a green tank, suggestions?

 

I bet your nutrients include phosphate.

 

Any sunlight hitting the tank? How much air vs co2 do you have entering the tank?

 

Are you injecting CO2 or using a carbon-substitute like Excel or Metricide 14? How much CO2 are you injecting? What ferts are you dosing (how much and how frequently)?

I bet your nutrients include .

In planted tanks, green water isn't associated with excess phosphates. It's more to do with some sort of imbalance in the fert-light-nutrient equilibrium, generally a deficiency in a macro nutrient (either nitrogen, phosphorus or potassium).

In fact, some people overdose on phosphate to eliminate green spot algae in planted tanks.

 

Algae, Part 2: Getting Rid of the Stuff (The Skeptical Fishkeeper) | Aquarium Basics | Columns |

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He states when he changes water it gets worse.

If the nutrients include phosphate and also the water change supply that's an issue.
The API test kit itself on the front says high phosphate high algae growth.

 

See post 8 by Tom Barr at this thread on thebarrreport.com. He dispels some common myths around phosphate and its supposed relationship with algae blooms by citing more recent research.

Mr Barr, in addition to being the developer of the Estimative Index method of planted tank fert dosing, is generally considered quite authoritative on matters of planted tanks.

It's been the consensus for a few decades that an excess of a given nutrient is not the culprit for algae blooms in planted tanks.

Regarding the water changes, it's more likely that they are diluting the pre-existent insufficient concentration of nutrients, creating more opportunities for microalgae to bloom.

The addition of CO2 without adequate fert dosing often leads to algae blooms of all sorts.

 

Tom states in post 8 that excess PO4 [phosphate] will induce algae growth. The paper is sadly no longer available. Would have loved to have read that one.

 

"They have found no correlation between PO4 in lakes with macrophytes and algae."

"I have a non CO2 low light tank as well, if you think I've not added excess PO4, and I mean a lot, you would be mistaken, I've added 2-3ppm there, same thing with NO3, Fe etc.

Never was able to induce algae if the system was well planted and doing well to start with."

I think the "the excess PO4 is going to induce algae" is supposed to have a "not" in there: Mr. Barr is well known for his long posts and ellipses!

Again, a cursory search through either planted tank or thebarrreport.com will find many threads/posts that emphasise that "PO4 =/= algae".

But again, there are caveats: this is for planted tanks with sufficient plant biomass. If we're talking about CO2 injection, I'm assuming that the tank is moderately to heavily planted.

Here's a thread at planted tank discussing phosphates and algae. Tom Barr (under the username plantbrain) is the author of post #4.

Hoppy, another generally authoritative planted tank expert, writes in that thread in post #6: "I think that "balance" is much less important than some others think. As long as you have good CO2, consistent with the amount of light you have, and have non limiting amounts of all the other nutrients, it doesn't matter if you have 2 or 3 times the recommended amount of any one of the nutrients, as far as algae problems are concerned."

 

Okay let's look at this another way. OP is stating problem is getting worse after water changes. If the plants he has can't take in the nutrients those levels will elevate which the single cell floating algae is rapid on. It's known some municipalities add phosphate to protect water lines. This suggests some level of nutrient is actually increasing in his tank with the water changes. It may not be phosphate but it's a reasonable assumption and must be ruled out.

 

Get a UV sterilizer for green water. Not a perma fix for nutrient imbalances or whatever is the cause I dunno but it will at least clear the water up.

 

The gist of Tom Barr and Hoppy's posts is that if all nutrients are non-limited (i.e. there isn't a deficiency in the supply of any given macro or micronutrient), then any excess nutrient of phosphate, nitrate, etc. won't cause algae growth. It's not the excess of any given nutrient that causes algae growth, but rather a deficiency in one or more specific nutrient.

If the OP isn't dosing sufficient ferts, then any water changes are simply diluting a limited nutrient supply to a degree that is even more limited, allowing algae more opportunities to outcompete plants for growth.

The OP shouldn't be asking "are my phosphates in excess?" (or for that matter, ammonia or nitrate given that they're present in tap water as well), but should instead be asking "what nutrient(s) am I lacking?".

As an example, I add 241.2 mg of PO4 (1.34 ppm) three times per week for a total of 723.3 mg of PO4 (4 ppm), much of which is in excess, and I don't have green water. That's because all my other nutrients (nitrogen, potassium, iron, calcium, magnesium and other trace elements) are non-limited.

 

If it's a lack of nutrients then I would expect his main plants aren't doing well. I wonder if that's the case.

 

I would suggest doing a water change and then a total blackout for about 4 days, put an airstone too to aid in surface agitation. Plants will look misserable afterwards but it gets the job done. Then work in balancing the light, nutrient & co2 of the tank. Perhaps decreasing the hours of light to six then gradually increasing weekly until it reaches 8 hrs, set the co2 to 30ppm and look into EI dosing.

Another fix for green water is investing in a UV sterilizer. It will clear it up in 1 day.

 

The gist of Tom Barr and Hoppy's posts is that if all nutrients are non-limited (i.e. there isn't a deficiency in the supply of any given macro or micronutrient), then any excess nutrient of phosphate, nitrate, etc. won't cause algae growth. It's not the excess of any given nutrient that causes algae growth, but rather a deficiency in one or more specific nutrient.

If the OP isn't dosing sufficient ferts, then any water changes are simply diluting a limited nutrient supply to a degree that is even more limited, allowing algae more opportunities to outcompete plants for growth.

The OP shouldn't be asking "are my phosphates in excess?" (or for that matter, ammonia or nitrate given that they're present in tap water as well), but should instead be asking "what nutrient(s) am I lacking?".

As an example, I add 241.2 mg of PO4 (1.34 ppm) three times per week for a total of 723.3 mg of PO4 (4 ppm), much of which is in excess, and I don't have green water. That's because all my other nutrients (nitrogen, potassium, iron, calcium, magnesium and other trace elements) are non-limited.

I am not a Tom Barr addict, but I think you've hit it Minnowette.

A lack of certain ferts !

 

I agree with terabyte. Get a uv light filter. We did that for our tanks and the water has remained crystal clear. No green tint or cloudiness at all!

 

Too much light.