Diatoms - Phosguard with Sponge Filter?

Hello – I know this topic has been discussed ad nauseam, however I have a few questions that I can’t seem to find the answer. My 10 gallon tank has been plagued with diatoms for 2 years. The tank is 4 years old so it's not new tank syndrome. I never had an issue until after about a year and a half I added some bagged sand from Petco. I think that may have been the issue. After a few months the diatoms started and I’ve now had them going on two years. I have tried:

Less light
More light
Adding water flow (which I can't now because I have a Betta)
Small daily water changes for a month
Taking everything but the fish out and cleaning with peroxide (twice)

It just keeps coming back!!! I even tried adding some Otos, which it turns out are very difficult to keep. I’m sad to say the last one died off. I was able to keep that one for about healthy for about 8 months. I was going to try some nerite snails but before I do, how would I use Phosguard with a sponge filter? Here are the parameters:

10 gallon
2 sponge filters - one at each corner
Sand substrate
Heavily planted - a huge anubias, 4 medium anubias, 3 moss balls
Temp - 75 F
Ammonia - 0 ppm
Nitrite - 0 ppm
Nitrate - 10 ppm
pH - 7.0
GH - 120
CH - 60
One male betta, one bumblebee goby, 2 panda cory catfish.

Any help, tips, would be greatly appreciated - thanks!!!

 

Do you have a old small HOB you could use? You could cycle the Phosguard through it in a rubber tub before doing your water change? You could add a heater to the tub so you can just dechlor and dump it in.

 

Hi - unfortunately, I don't have an HOB filter. I recently changed from an internal Aqueon carbon filter to the sponges.

 

That could work if it has a chamber to put the phosguard in. I would put it in a fine media bag though.

 

Can I use a media bag directly in the water? I only have sponge filters. Or are there any other suggestions on getting rid of diatoms?

 

Other than that I dont think a bag just sitting in there will do much. Maybe you could put a air stone in the media bag? Do you still have the sand from petco or whatever? Maybe you should just change it.

 

The sand from Petco was added to the live bio sand I bought when I set up the tank over a year after the initial setup. I added some around the plant roots. Assuming that had silica in it would changing the sand fix the issue? The brown is everywhere now and it’s been a two year battle. Takes me over an hour a week to clean the whole tank and the plant leaves get cracked no matter how gentle I try to be when cleaning them. The whole process is such a chore it sort of takes the fun out of the hobby. I mean I know there’s work involved but for a 10 gallon tank I should be doing a 15 minute water change/vacuum every week. The odd thing is I added a small anubias plant about 7 months ago and it’s the only thing that doesn’t have any diatoms on it.

 

That is really strange for it to be happening for so long. I can see why it would be frustrating. Maybe MacZ may have some insight of why this could be happening.

 

Can I use a media bag directly in the water? I only have sponge filters. Or are there any other suggestions on getting rid of diatoms?

I’ve tried that and it didn’t work for me. I had put it directly in my filter outlet.

On my 75 gallons tank, it started working when I put it directly into my canister filter. On my 13.5 gallons, I put the bag near the water stream in the chamber. It’s a much smaller volume so that was enough.

Since your tank is small, you could try putting the bag directly under a power head. There has to be good flow through the beads or it won’t work.

If that doesn’t work, then it’s one case where I would recommend buying the cheapest canister filter possible, like a Sun Sun, and put the bag inside the canister filter.

On the bag it says it’s best to use less, but in my 75 gallons I had to use at least 4-5 times what the instructions say, if not more. On my 13.5 gallons, maybe twice the amount.

It comes back as soon as you stop using Phosguard. This stuff is hard to get rid of !

 

Well thanks everyone for the tips - is phosguard safe for the fishes? I imaginw it is, but if I need to buy more equipment and keep using it, I may try some nerite snails first.

 

Yeah they should work. They are bio eating machines.

 

Well thanks everyone for the tips - is phosguard safe for the fishes? I imaginw it is, but if I need to buy more equipment and keep using it, I may try some nerite snails first.

As far as I know Phosphate is safe. My fish don’t mind It. Corals (saltwater tanks) don’t do well with it though but it’s because they need phosphate.

I have snails in my saltwater tank and they can barely keep up even though they’re very voracious eaters. I have 5 in my 13.5 gallons.

 

Assuming that had silica in it would changing the sand fix the issue?

StarGirl what are you summoning me for, the OP has found the problem on their own.

It's silica, but that doesn't mean it has to come from the sand, it can also be dissolved in the tapwater.

 

Diatom shells are composed largely of silica. Thus, you have to have a lot of silicates in your water. Even if your sand brought silicates into the tank, eventually the dissolved silicates should diminish and the diatom bloom should go away. It sounds like you have a continual input of silicates.

Check with your water supplier to see if your tap water contains silicates. I suspect that it does. If the tap water is the source of your silicates, it may be easier to treat the tap water with a phosphate remover than treating the entire tank. Silicates and phosphates are similar in chemical structure, so the same product removes both.

If the tap water is the source, you might be able to pass the water through a reactor filled with something like Granular Ferric Oxide as you fill your aquarium.

 

That is interesting about the tap water. I recently moved - about 3 motnhs ago - and still have the diatom problem. Plus I have another 10 gallon tank that is all dwarf shrimp and there are no diatoms even though I'm using the same tap water. I'll give the snails a try and see how they work out before adding any chemicals - thanks everyone!!

 

That is interesting about the tap water. I recently moved - about 3 motnhs ago - and still have the diatom problem. Plus I have another 10 gallon tank that is all dwarf shrimp and there are no diatoms even though I'm using the same tap water. I'll give the snails a try and see how they work out before adding any chemicals - thanks everyone!!

It doesn’t have to be the water. It can be rocks, or sand. In my case it’s probably both the rocks and the sand.