Randy's Tank and Learn Thread

johnnycamp5 · Jul 9, 2025

Randy Holmes-Farley said:
No idea how to characterize it. Ordinary saw I’ve had for 40 years. Meant for wood, but it cut through the rock reasonably well. Not appreciably harder than cutting through a hardwood. :)

It looks like an old Mitre saw (minus the box of course)

rtparty · Jul 9, 2025

Randy Holmes-Farley said:
Magnesium Considerations

In my last tank I supplied all calcium and alk via kalkwasser, so I needed to dose magnesium, and to do so I added extra to my AWC water. The beauty of that plan is mag cannot ever rise higher than the new salt water. Thus, no testing was ever needed.

I’m going to do the same now that I use AFR on this tank. Let’s see how much I’d need.

Currently I’m adding about 12 mL of AFR per day. That’s not actually measured, just based on the doser 1.1 mL per min claim (which Miami says is off, but let’s go with it).

At 43,000 ppm calcium for AFR, that is adding about 0.5 grams per day of actual calcium. At 1900 ppm magnesium, it is adding 0.023 grams of magnesium.

By RMM, I choose to add mag at 10% of calcium, or 0.05 g of magnesium total per day. That is 10% of the calcium. Thus, I need to add 0.05-0.023 g Mg =0.027 g per day.

Since I am auto changing about 2.5 gallons (9.5 liters) per day, I need to effectively add 0.027 g Mg per 9.5 liters = 2.8 ppm of magnesium to my new salt water. It’s hardly enough to even bother with, but I will. It’s also not enough to worry about ionic balance, so I will use the old bag of Epsom salt I gave.

I make up about 80 gallons (300 L) of salt water at a time, so I need 2.8 ppm in 300 L, which will be accomplished using 6 g Epsom salts (using the chem calculator).

Easily done. I’ll change it in the future if the AFR dose changes significantly.

I fully understand Part C is not meant to be used this way but I have 3-4 boxes of it leftover.

Can I use it to add a little magnesium to my systems along with the AFR?

Randy Holmes-Farley · Jul 9, 2025

rtparty said:
I fully understand Part C is not meant to be used this way but I have 3-4 boxes of it leftover.

Can I use it to add a little magnesium to my systems along with the AFR?

It will also give a little boost to potassium. 1/3 as much as the magnesium. That might or might not be an issue in any given tank. I don't expect any other likely issues from it.

rtparty · Jul 9, 2025

Randy Holmes-Farley said:
I will also give a little boost to potassium. 1/3 as much as the magnesium. That might or might not be an issue in any given tank. I don't expect any other likely issues from it.

My belief is anything too haywire is outweighed by weekly 10% water changes.

Is the formula roughly the same as yours above?

Randy Holmes-Farley · Jul 9, 2025

rtparty said:
My belief is anything too haywire is outweighed by weekly 10% water changes.

Is the formula roughly the same as yours above?

I expect so, yes. Part C is mostly Epsom salt and the RMM percentage to pick is guesswork anyway.

Randy Holmes-Farley · Jul 9, 2025

Randy Holmes-Farley said:
I expect so, yes. Part C is mostly Epsom salt and the RMM percentage to pick is guesswork anyway.

Actually, I take that back. I'm not certain how they make it. Here's an old DIY salt recipe. If you take away the NaCl, the next two big ingredients are mag chloride and sodium sulfate. That could also be done with mostly epsom salt, but if made as below, its adding more sodium and chloride, and hence less mag and sulfate. So the recipe I gave would be the most potent it could be, and real ways of making Part C will contain less mag, but still be Ok to use.

23.98 g	sodium chloride
5.029 g	magnesium chloride
4.01 g	sodium sulfate
1.14 g	calcium chloride
0.699 g	potassium chloride
0.172 g	sodium bicarbonate
0.100 g	potassium bromide
0.0254 g	boric acid
0.0143 g	strontium chloride
0.0029 g	sodium fluoride

Water to 1 kg total weight.

rishma · Jul 9, 2025

Randy Holmes-Farley said:
Magnesium Considerations

In my last tank I supplied all calcium and alk via kalkwasser, so I needed to dose magnesium, and to do so I added extra to my AWC water. The beauty of that plan is mag cannot ever rise higher than the new salt water. Thus, no testing was ever needed.

I’m going to do the same now that I use AFR on this tank. Let’s see how much I’d need.

Currently I’m adding about 12 mL of AFR per day. That’s not actually measured, just based on the doser 1.1 mL per min claim (which Miami says is off, but let’s go with it).

At 43,000 ppm calcium for AFR, that is adding about 0.5 grams per day of actual calcium. At 1900 ppm magnesium, it is adding 0.023 grams of magnesium.

By RMM, I choose to add mag at 10% of calcium, or 0.05 g of magnesium total per day. That is 10% of the calcium. Thus, I need to add 0.05-0.023 g Mg =0.027 g per day.

Since I am auto changing about 2.5 gallons (9.5 liters) per day, I need to effectively add 0.027 g Mg per 9.5 liters = 2.8 ppm of magnesium to my new salt water. It’s hardly enough to even bother with, but I will. It’s also not enough to worry about ionic balance, so I will use the old bag of Epsom salt I gave.

I make up about 80 gallons (300 L) of salt water at a time, so I need 2.8 ppm in 300 L, which will be accomplished using 6 g Epsom salts (using the chem calculator).

Easily done. I’ll change it in the future if the AFR dose changes significantly.

I don’t have AWC on my current tank, but have in the past. I really like the idea of spiking the AWC water with things we want to dose but I had never considered it.

One could add magnesium, and maybe TM A & K, iron, manganese? I’ll file this idea away for later.

rishma · Jul 9, 2025

Randy Holmes-Farley said:
Might be The TDO chromoboost which I heard is high in P.

I can confirm TDO is relatively high in P. I used it for 2 years, when I got a fish that would only eat frozen I stopped and my P started trending lower and lower. I had to start dosing until I found a mix of foods to keep it elevated.

Randy Holmes-Farley · Jul 9, 2025

rishma said:
I can confirm TDO is relatively high in P. I used it for 2 years, when I got a fish that would only eat frozen I stopped and my P started trending lower and lower. I had to start dosing until I found a mix of foods to keep it elevated.

Thanks. :)

Randy Holmes-Farley · Jul 9, 2025

Phyto Dosing

After reading a bit on how copepods feed, they do not need to visually detect Phyto, but do it by physical and chemical means. They also often do it at night, though that is mostly for free swimming pods to prevent predation by swimming up toward the surface during the night and back deeper during the day. I found nothing about the natural time of day feeding for benthic pods.

With that as backdrop, I moved my phyto dosing to the night. Also moved the skimmer 2 h shut down to follow it, and the 10 min phyto stirring to precede it.

A new batch of Reef Nutrition phytofeast live should arrive today, as the first 32 oz bottle is about gone.

The mandarin is doing super well, growing fast, and I want to keep that up. Turns out that I’m getting more Apo pods along with the anemone next week since it actually saved money to get them by pushing the Pacificeast order into free shipping (it was once cent below free shipping). lol

Randy Holmes-Farley · Jul 10, 2025

New corals

I went out to visit Acrogarden, which is a local farm run by Dong Zou. Lots of great healthy corals. Sadly for most of you, he doesn’t ship. But he did give me two corals, a Bali Green Slimer and a PC rainbow. He even dipped them (KCl) which he says he always does for corals he sells.

Both are in my tank now and the green slimer is living up to its name. lol

Here are some pics a few minutes after glueing then down (a process that still stresses me, but I’ll get used to it).

Randy Holmes-Farley · Jul 10, 2025

Bruiser of a Crab

This red mithrax crab is getting huge. Maybe it will train those big pincers on the mantis shrimp. My wife took this video where it seems to be crunching shells in its claws and putting them in its mouth. Maybe it is scraping algae off them. It spends a lot of time cruising the rocks grabbing constantly at the surface, presumably getting little algae bits.

johnnycamp5 · Jul 10, 2025

@Randy Holmes-Farley
Why does it stress you to glue down the coral?

JonoH · Jul 10, 2025

Randy Holmes-Farley said:
New corals

I went out to visit Acrogarden, which is a local farm run by Dong Zou. Lots of great healthy corals. Sadly for most of you, he doesn’t ship. But he did give me two corals, a Bali Green Slimer and a PC rainbow. He even dipped them (KCl) which he says he always does for corals he sells.

Both are in my tank now and the green slimer is living up to its name. lol

Here are some pics a few minutes after glueing then down (a process that still stresses me, but I’ll get used to it).

Awesome size frags!

EliMelly · Jul 10, 2025

JonoH said:
Awesome size frags!

Those aren’t frags lol

JonoH · Jul 10, 2025

EliMelly said:
Those aren’t frags lol

Was thinking they were more like mini-colony's

Randy Holmes-Farley · Jul 10, 2025

johnnycamp5 said:
@Randy Holmes-Farley
Why does it stress you to glue down the coral?

I have little experience with gluing corals. I never glued anything in my old tank. All were colonies big enough to just set in place. It just seems harsh to be holding and pressing them, hoping the glue sets to be able to let go, etc. lol