mbrant

I have a 90 gallon heavily planted tank that was purring along just fine and then a few months ago started to develop green hair algae (grows from the leaves of some plants much more than others). The tank has been going for over a year.

Some basic information:

• 3 96 Watt Power compacts (50/50 daylight bulbs) suspended about 4 inches over uncovered top. 12 hours of lights-on.
  
• Co2 Injection using ph Controller. Controller set to 6.5. ph closer to 6.8-7.0. Two Aquarium Guild CO2 reactors.
  
• UV Sterilizer set to run when the lights are off.
  
• Temperature about 77-79 F. provided by undergravel heat coils and Azoo 300watt heater.
  
• Eheim 2226 and Eheim 2222 Cannister filters.
  
• 3 inches of Eco Complete substrate.

Fish:

• 6 Ottos
• 12 Cardinal Tetras
• 10 Rummy Nose Tetras
• 6 Candy Cane Tetras
• 3 SAEs
• 3 Yoyo Loaches
• 4 small clown loaches.

I do 30% water changes 2 times a week.


The problem may have started when I tried adding liquid fertilizer supplements. I stopped adding suplements when the algae got bad.

I have no measurable Nitrates or phosphates or potassium.

The plants are growing and reproducing but have a yellowish tinge to the leaves which is why I started fertilizing in the first place.

Any suggestions?

mbrant

From the algae finder it looks more like the fuzz algae than the green thread.

Mr. Fish

I'm actually at war with this issue aswell and trying to figure
out the cause.
Is your water hard?
Whats your parimeters?

For now cut back on your hours of photosythensis to 7 hours intill we figure out the problem

mbrant

I was a bit surprised but I just tested hardness and

KH= 10
GH=17.

I have an R/O unit, but I haven't used RO water on this tank in many months (obviously).

Does the high hardness explain why it's been difficult to get the ph down to my target (6.4-6.5)? I seem 'stuck' at 6.8.

Should I start using RO water on my water changes?

Might this explain my problems?

hoppycalif

You can't just select a "target" pH and expect the controller to make the water have enough CO2. You need to use a drop checker, with known 4dKH distilled or DI water in it to set the bubble rate so you have about 30 ppm of CO2 in the water. Then when it is stabilized at that value, measure the tank water pH and set the controller to that pH. Now, the controller will keep the concentration at about 30 ppm, unless something changes in the water - KH drops or rises or tannins lower the pH, for example. So, you really need to recheck the water with the drop checker every few days to be sure you are still keeping th ppm of CO2 where it belongs. Don't use RO water unless you are keeping some fish that absolutely have to have soft water, or if you are growing plants that absolutely have to have soft water. Otherwise you just add one more variable to the water parameters that has to be kept stable.

mbrant

Do you need to measure the CO2? I have a chart from the Optimum Aquarium that shows you can determine the correct CO2 content by comparing the KH to the PH. Is this not correct?

Cliff Mayes

Wow! Where did you get the Optimum Aquarium from? I bought that when it first came out for about $6. The current prices are incredible.

It is valauble now for its historical value. I am not sure that it ever made any sense for the average hobbyist. The Germans did stand this Hobby on its ear when they started with the light and chemical dosing. That was a long time ago and I think that the book was published to ride that crest.

The info in Optimum Aquarium is interesting but just do not get too confident in it. I just saw, recently, that someone referred to it but I cannot remember why.

You are being given the best and most recent advice about pH and drop checkers.

mbrant

Thanks.

I've been fighting the good fight for many years. I bought my copy of the Optimum Aquarium when it was available. I've even got the VHS tape around here somewhere.

I will get the drop checker set up. Thanks for the guidance Cliff, HoppyCalif, and Mr. Fish.

mbrant

Any suggestions for how to get rid of it? I've got some Amano Shrimp on order. Anything else?

I'm most puzzled by how the algae is flourishing in the absence of Phosphates and Nitrates. Any ideas on that?

hoppycalif

Nitrates and Phosphates are not a cause of algae. That has been demonstrated many times. Algae require very little in the way of nutrients, far less than plants require. Primarily they require light. Then, to signal the spores to start growing a crop of algae they rely on detecting small amounts of ammonia in the water or wildly fluctuating concentrations of CO2 in the water, plus probably several other conditions differing for various algae.

Having stable CO2 concentration day after day, plus having lots of growing plants to consume any small ammonia surges almost instantly are things that deter algae from blooming.