Will algae (staghorn!) grow without phosphate?

[Sophia]

So... the staghorn saga continues! For those who have been giving me advice over the last few months, where I'm up to now is that over a 3 or 4 week period I had the phosphates tested twice and the colour reading went from 0.5-1ish down to 0.5. This I attribute to the fertiliser schedule started at the beginning of that time that was designed to boost the plants into sucking up phosphate.

Over the last couple of weeks-ish there have grown maybe 10-20 small branches of staghorn present in the area where I had it last time, where the sunlight hits (an hour or 2). More this week than last but maybe just because now they are big enough to see! I have cut off these leaves.

The questions is, if I go to the trouble and expense of buying a phosphate kit and some phosphate remover, do you think the staghorn will still grow? I could buy some algae rid and dose the tank with that (or dose the plants outside the tank) but we know that just kills the symptoms and that is still a last resort. I really want to try and conquer it without going that far if possible. Trying to pinpoint the real source of the imbalance is starting to feel like not fun, I find it hard to believe just a little sunlight could cause this after seeing other people's tanks sitting in the window and just suffering a bit of green water!

Other things I've done different ..

This week - Reduced the time the light is on to noon to 9pm instead of 10am till 9pm.

Changed algae wafers from Aquarian brand which are thin and break up to JBL which I discovered do not disperse and sit there forever (probably making more phosphate, even though the label says it's OK to have them sitting around! Have only had one of those mistakes so now feeding half a chip.

Since a week or so ago - reduced daily dose of flourish excel from daily mini recommended dose to small dose weekly at water change, even that causes cloudiness though so it's likely I will give that up altogether.

Dosage for flourish comp. is Mon/Wed/Fri normal dose + normal dose at water change on Sat.

Since Sat noticed the beard algae has regrown on the log - is that normal for wood anyway? I notice most of the nice tanks on display don't have algae covered logs!

Amm/Nitrate/Nitrite all as low as usual.

Fish are all as happy and active as usual. Tonight they are grumbling because I am starving them in an attempt to lose some phosphate after discovering that chip on in the gravel. They said they were saving it for a midnight feast... :roll:

[Jennifer]

Phosphate (PO4) limitation will decrease the growth rates of plants by reducing the plants' demand for all other nutrients (including CO2 and light). You can get indirect algae control by limiting PO4 but if you don't want plants to grow in the first place you shouldn't have strong lighting (intensity or photoperiod). In other words, PO4 is a band aid for the problem, however, it doesn't solve the problem. Addressing the problem has more to do with growing plants than with controlling algae. Unlimiting CO2, unlimiting nutrients and low light are all ways to grow plants that produce moderate biomass while safely limiting conditions that favour algae. You can get slightly more growth by using low CO2 and high lighting but the chances for algae will be higher. Incidentally, in a high tech setup, high lighting, unlimiting CO2 and unlimiting nutrients will cause double the plant growth rate in ideal circumstances but the balance is much finer and careful monitoring of CO2 and nutrients is necessary to keep plants growing optimally and thus prevent algae under the high lighting conditions.

Ammonia will cause algae. Even a cycled tank can have a temporary ammonia spike under the right conditions (e.g. rotting excess food, rotting dead fish) so make sure the these conditions are not occurring.

Best rule of thumb: lower the light levels even more, provide good CO2 (DIY CO2 would be a good start) and keep the tank clean (many plant experts recommend keeping a clean filter as well - I am not sure that I believe this but I am starting to see evidence that this is beneficial in my own practices with higher tech planted tanks). Give the plants a week before each change to allow them to adjust.

Some other observations: Remove what algae you can see. The BBA will go with the introduction of DIY CO2. Sunlight will not cause algae in the right conditions. In fact I have started allowing an hour of sunlight on three of my tanks and they have never looked better. Dosing with daily trace (including potassium) will help the plants to absorb PO4.

[Sophia]

I can increase the F.Comp to daily (as you suggested in the first place!)

I will look into DIY Co2 but so far it hasn't been an option for me - not enough space or time/inclination.

Do you know why the F.Excel causes cloudiness nowadays? Is it a bit like taking Vitamin C - what you don't need you pee out, what the tank doesn't need it's messes up the water with?!

How long should I reduce the photoperiod by this time? Is 3 less hours too much of a drop?

[Jennifer]

Yeah go ahead and reduce the photoperiod to around 6 hours. It would be good to try CO2 injection but if you can't manage that, keep going with the Excel. Feed very lightly, clean the tank and keep dosing with trace.

If after 2 weeks of the above there is absolutely no improvement, try a complete blackout to initiate a die off - 2 days of blackout to 5 days of light and repeat every week for a month.

[Sophia]

oh and I also now have a big chunk of windelov fern sucking up evil too

so the thing I get out of this is probably though I feed what they eat in a couple of mins (algae wafers not counted), I have probably still been feeding too much. Because where else would the phosphate come from? While the tank water had gone down slightly, the tap water was zero, so it must be whatever I'm adding.

thanks again

[alanmin4304]

Overfeeding and the wrong food or both is usually the source of phosphate. Cut right back. Your fish don't need as much as you think.

[Sophia]

it's been hard to find a balance in feeding as the tetra will take the shrimp pellets but the cories can't eat the flakes so I had been giving a bit of each. The cories can't eat the white worms and the grindals don't sink quickly enough to make it to them either! Makes it easy to see why people have single species tanks with these kinds of little issues.

now they will have to make do with sharing shrimp pellets until I get the rest under control

in other news there is no new staghorn since I removed the last few bits, so there's a bit of good news for now

[Jennifer]

in other news there is no new staghorn since I removed the last few bits, so there's a bit of good news for now

Excellent progress.