[bob.bonnet]

I would really like some advice to address some staghorn algae. My 29 gallon tank is about 3 months old. What I believe is Staghorn started about a month ago and has steadily worsened, regardless of what I do. All slow growing plants in the light are infested. First, I bumped the injected CO2 up to result in a full Ph drop. Drop checker slowly goes to yellowish green with no fish reaction. CO2 on 2 hrs before lights start to ramp up and off 1 hr before lights off. No improvement. Then I reduced lighting. (I have 2 AI Prime Freshwater LEDs) reduced to 6 hrs/day plus 1 hr ramp up and down @ 35% - it had been 40%. After 2 weeks, reduced further to 5.5 hrs @ 30%, where it is now. No improvement and the tank looks dark. Started spot treatment with h2O2. Turned algae reddish in spots and melted some buce, but I am still losing the battle. Then I tried a 3 day blackout. No improvement to algae, but my stems did not like it. I do have lots of ambient light in this room, but have not addressed this (when the sun was lower, I did get some direct light on the tank in early morning.) I trim some of the worst infected leaves, but these plants grow so slowly, I hate to do it. Now the buce are not looking good - still get new leaves, but many melt away in the algae, and I believe some of the rhizomes are dying.

Now I am getting an algae which Iooks similar, but more black and seems more dense (see photo of buce with Neons) Not sure if this is something else. I do have a couple small spots of black brush algae.

Tank parameters:

• I guess medium planted - see photo. Mostly slow growers.
• Ph - 7.6 reduced to 6.6 with CO2
• Ammonia & Nitrites 0 (no spikes since first cycled)
• Nitrates 20 (this has been steady)
• Gh 12, kh 9 (RO mixed 50% as my well water is twice this)
• My lfs tested my water and says phospates are a little low for the Nitrates (I do not know the number)
• Cleanup crew - 10 Amanos, 10 cherry shrimp. 12 Ottos
• Water changes 15-20% twice a week because of shrimp
• All in one ferts by UNS (from Buceplant) One squirt every day - I have not altered this.
• No tank heater - water about 72 degrees
• Oase Biomaster 600 filter - way oversized for this tank
• Inline CO2 diffuser

The tank parameters have been very steady and I check them frequently.

Where do I go from here? Lights up, fertilizer up, larger water changes (but the shrimp?). I hesitate to do a full tank chemical treatment as the algae returns where I spot treat it, but now the plants are suffering. I am at a loss.

Thanks for any help - Bob

 

[EdWiser]

What is your phosphate level? The main issue is phosphate level.

 

[Sequoia Exotics]

Try siphoning out and manually removing as much as you can, then dosing Seachem Excel for a while. Strong plant growth is the best defense against algae so I would be careful leaving the light low for so long. Instead try setting a siesta period. If your not familiar with this, it is essentially were you turn off the lights for a break in the middle of the day. Apparently aquatic plants can start photosynthesizing in as little as 30 min, but algae needs many hours of direct light. If you turn off the lights for a couple hours in the middle of the day, the plants get plenty of light but the algae can't grow. (So a possible photo-period could be 3.5 hours light, couple hour break, 3.5 hours light, off for the day)

Just keep doing the best you can to remove the algae manually-- and if you keep nutrients and light at the right level, your plants should make a come back, and outcompete the algae.

 

[EmotionalFescue]

Some thoughts...

Kh still seems high with your RO cut water. I have struggled with algae with water that hard in a way that I have not with kh closer to 2.

Uns all in one is pretty rich with a nitrate to phosphate ratio of 4.6. your aquasoil is probably soaking up the phosphate. So your root feeders probably have access to plenty even if it's not rich in the water.

What is your outflow situation? I have become a strong believer in good flow being near the top of the list for plant health factors. A spraybar might really help.

 

[Stan510]

I think this will help more than me typing it.

 

[bob.bonnet]

Thanks for responding everyone. EdWiser; I do not know the actual phosphate level. The lfs guy just said it was a bit low, but said he was reluctant to recommend I add any. I wish I had the actual number, but are you suggesting I dose phosphates? Is too much phosphate a problem? Sequoia Exotics; I also am concerned that I am starving the plants for light. They are strong lights, but cut so far back. But he algae only grows in the direct light. I had not heard of those advantages of a siesta period - I can try that. And yeah, trying to get the nutrients and lights at the right levels seems to be the key... EmotionalFescue; I can try a higher % of RO water. I take it you think my phosphates are not a problem? I do have ADA Amazonia aquasoil covering ADA PowerSand and have been dosing the all-in-one fertilizer since the beginning (3 months). And the filter is oversized - it claims 330 gal/hour flow in my 29 gallon tank. The flow is quite strong - the fish can't handle certain parts of the tank. Do you think I really need more? Stan510; Interesting video. I have been toying with a full tank Excel treatment, and expect it would kill the algae, but it will just grow back unless I get the tank balanced. I did spray h2o2 on some of the moss and buce at a water change. It killed the algae, and melted the buce - and the algae is now growing back.
Again, thanks everyone for your thoughts. Trying to get everything in balance is surely a challenge.

 

[EmotionalFescue]

It seems to me like you're dosing enough phosphate.

I don't think you need more flow, but you might need better flow (and maybe even fewer gph). I've been the most successful with a gental uniform flow from back to front via a spraybar. Your mileage may vary of course.

I do think softer water might make your life easier.

 

[EdWiser]

No you don’t want to dose phosphate you want as little phosphate in the water as possible. It’s the basis for almost all algae issues. Algae grows due to an abundance of phosphate in the aquarium. Over the years many suggest doing very large frequent water changes. Issue with this is that most don’t want to put in the time. An most are not using RO/DI water. While you can use stuff to fight it. Unless you get your water under control you will not defeat it.
Using a phosphate removing compound in your filter and change it out once amount. An using RO/Di water. Will help you gain control of your water quality.
Learned this thru 50 years of fish and coral keeping.

 

[bob.bonnet]

Thanks again for responding. I will not dose any phosphates, but why would I need a phosphate removing compound when it is already low? I will bump up my RO/DI percentage, increase water changes, experiment with flow, be more aggressive manually removing bad spots, and try a siesta period for the lights. Should I also increase the duration and/or intensity of the lights? - the green algae on the rocks and sand in the front is getting worse. Is the ambient light a problem?

 

[EmotionalFescue]

You're going to see a lot of conflicting statements on phosphate and it can be very frustrating and annoying to try and navigate on your own.

Some people are going to tell you that phosphates cause algae, and some people are going to tell you that phosphates do not cause algae lol.

I think it's generally really useful to pay attention to how the most successful tanks are run. I also think you'll find that many aquarists on this site with beautiful tanks are dosing phosphates at levels similar to yours and are focusing on plant health first and foremost. That doesn't happen in a vacuum of course and co2, light, flow, and tank cleanliness are all very important. For what it's worth, I have come to believe that setting fertilization at reasonable levels while you really dial in all those other things is a good approach.

Until you're out of the woods, water changes are your friend.

 

[Sequoia Exotics]

Yeah, I would agree. Focus on maintaining the minimum for great plant growth (if that means they need their old light intensity back, do that) and be vigilant in water changes and manual removal. If you do a large water change at the end of each week or more frequently, you will have more leeway with ferts and nutrient levels. Keep up the good work!

 

[bob.bonnet]

Thanks again - Bob

 

[EdWiser]

Sadly most freshwater hobbyist are stuck in very old ways. I learned what to do thru testing and not by what is repeated by hobbyist constantly and get to the source of the problem. I concern is finding out the why and wherefore of an issue. So ICP testing and tracking of the aquarium doing experiments with different techniques.
I come from the saltwater side of the hobby where there is a constant striving to keep water parameters under control.
This type of algae also happens an it always leads back to excess