Algae is dying - do I need to buy more?

[njkalm]

Hi all,

My daughter and I started a shrimp tank for her birthday several years ago and it's been doing great - but we moved to a new apartment in August, and just noticed today that much of the macroalgae seems to have died off since the move. There's probably about 1/4th the amount that there was a few months ago.

My daughter's bedroom doesn't get much natural light, and so the tank hasn't gotten much light the last couple months. I started scheduling the tank's LED lights to go on during the day, and I'm opening the curtains as much as I can, but it's still a relatively dark room.

Should I be patient and hope that the algae starts to grow back? Or should I buy more to try to replenish the supply and hope that this helps to get things back to where they were? I'm attaching a photo in case that helps...

Thank you!

Noa

[Tiny Ocean]

Judging by how pale the alga is, it is definitely not getting enough light. Try moving it about 2 to 3 feet from a good window for a month and see how it performs.

[Tiny Ocean]

Would a smaller tank allow you to place it nearer a good window? For so few shrimp, you really do not need such a large tank. A smaller tank with just one very holey rock would provide enough water and better habitat. One gallon can hold 20 shrimp quite well.

[njkalm]

Judging by how pale the alga is, it is definitely not getting enough light. Try moving it about 2 to 3 feet from a good window for a month and see how it performs.

Thank you for the input @Tiny Ocean. I'll see what we can do!

[Tiny Ocean]

Hello NJKalm, did the algae improve?

[Vorteil]

Actually you're wrong. There's not than enough light. This chaeto does not like high light. It does great under low level LED's. It's not getting enough nutrients. The chaeto has done it's job which is to remove ammonia, nitrates and phosphates.

[Tiny Ocean]

With so few shrimp to cycle nutrients to the algae, you may be right. But if there are MTS in there, they should provide nutrients. Normally if the available nutrients are low the chaeto stabilizes at a smaller size but stays deep green. The OP notes that the tank was okay until it was moved to a room with very little natural light.

[njkalm]

With so few shrimp to cycle nutrients to the algae, you may be right. But if there are MTS in there, they should provide nutrients. Normally if the available nutrients are low the chaeto stabilizes at a smaller size but stays deep green. The OP notes that the tank was okay until it was moved to a room with very little natural light.

Thanks for following up. Ultimately, the logistics have prevented us from being able to move the shrimp nearer natural light, so the chaeto have continued to be rather sparse and pale. I recently purchased a “grow light” (https://a.co/d/iJBXWsF) but am beginning to worry that it’s too strong (100watt) as it’s for plants.

I don’t know much about nutrients, but we’ve only fed the shrimp a few times ever as it seemed like they were doing well and reproducing and there was healthy chaeto growth. But could this be part of the issue? I was always a little worried about overfeeding and how the shrimp mostly ignored the food. Relatedly, I read something about dead/decaying chaeto not being good for the tank and now that has me concerned as well…

If moving closer to natural light isn’t feasible, would the right sort of aquarium light be able to provide the kind of lighting that is necessary, assuming that light is indeed the issue?

[Tiny Ocean]

Just don't stick the grow light adjacent to the tank and don't leave it on all the time -- at a rough guess I'd say keep it at least 6 ft away, and turn it off at bedtime.
Are you sure your salinity is okay? Is it the same as when the chaeto was flourishing?

[njkalm]

Just don't stick the grow light adjacent to the tank and don't leave it on all the time -- at a rough guess I'd say keep it at least 6 ft away, and turn it off at bedtime.
Are you sure your salinity is okay? Is it the same as when the chaeto was flourishing?

I just checked the salinity for the first time and it was right at 1.010, and just checked phosphates too, which were around .25. I also exchanged the grow light for a chaetomax, as the grow light was pretty intense. At this point much of the macroalgae is white. I read something about chaetogro and/or a sponge filter to increase water flow, which I’m open to, but I’m wondering if it might be better to get a new batch of macroalgae and see if I can keep the new batch alive rather than trying to resurrect the existing stuff which might be too far gone? Attaching some updated photos in case it helps.