cdawson

I hate starting redundant threads, but I need to get to the bottom of this.
I use the sears conlin recipe for PMDD, but have not included NO3. I get more than enough from my fish.
I have been experimenting with 2.5 ml every 2-3 days, but the GSA has come on full force. I'm concerned about the substrate, being 4" of flora base in a 135g throwing off any dosing or readings I may get. I haven't been able to find any list of ingredients for it.
ph is 6.4
kh 4
Iron 2.5-3 mg/l
No3 - around 12.5mg/l
Co2 - 24 ppm.
everything else I'm not sure of.
I have about 192 watts of CF lighting from two 36" jbj strips, and about 144 Watts of T5 daylight bulbs w/o reflector.
There aren't many fast growing plants in the tank though, water sprite and stargrass are really the only ones.
I've had absolutely no luck with this tank, and I have about 4 other planted tanks that are doing wonderfully.
I might add that this is the only tank using florabase, so my opinion of this substrate is not very high these days.
Any help is greatly appreciated, I NEED IT!

Simpte 27

PO4, PO4, PO4. Add some po4 and watch your problems disappear

cdawson

Yes, but people are always saying excess phosphates contribute to algae?
I hear so many conflicting ideas, and I don't have any problems in my other tanks with phosphates. If I do in any of my tanks it's because of an abundance.

I guess I'm going to get a po4 test kit today and find out exactly how much I have.
-Chris

BryceM

I had horrible GSA and almost no PO4. I now add about 2-3 ppm / week and the problem is solved. I still have a touch of BBA, but even that is slowing down now that CO2 is up.

cdawson

That must be the issue then, I don't add PO4 in any form right now.
I'll get me a test kit later today and see if it is the problem.
Thanks guys
-Chris

trenac

This use to be the norm of thinking, but more than likely it is just the opposite. It is very doubtful that you would have high P04 in a heavily planted tank.

cdawson

Thanks again guys, looks like that's the problem, I have almost NO phosphates in my water.
Another question, if I reduce the amount of CO2. That will decrease the amount of nutrients the plants use right?
Will that stop growth overall or simply slow the rate at which they grow?

BryceM

Reducing CO2 will decrease the rate of growth of the plants, but not necessarily of the algae. Tanks without CO2 are said to grow about 4-5X slower.

I strongly recommend that you only change one thing at a time though. The way to an algae-free tank is RARELY (if ever) by turning down the CO2.